Modulators of hemoglobin

ABSTRACT

The present disclosure relates generally to compounds and pharmaceutical compositions suitable as modulators of hemoglobin, and methods for their use in treating disorders mediated by hemoglobin.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/865,625, filed May 4, 2020, which is a continuation of U.S.application Ser. No. 16/687,474, filed Nov. 18, 2019, which claims thebenefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No.62/769,196, filed Nov. 19, 2018, U.S. Provisional Application No.62/821,314, filed Mar. 20, 2019, U.S. Provisional Application No.62/848,773, filed May 16, 2019, and U.S. Provisional Application No.62/883,313, filed Aug. 6, 2019, each of which is hereby incorporated byreference in its entirety.

FIELD

Provided herein are compounds and pharmaceutical compositions suitableas modulators of hemoglobin, and methods for their use in treatingdisorders mediated by hemoglobin.

BACKGROUND

Sickle cell disease is a disorder of the red blood cells, foundparticularly among those of African and Mediterranean descent. The basisfor sickle cell disease is found in sickle hemoglobin (HbS), whichcontains a point mutation relative to the prevalent peptide sequence ofhemoglobin A (HbA).

Hemoglobin (Hb) transports oxygen molecules from the lungs to varioustissues and organs throughout the body. Hemoglobin binds and releasesoxygen through conformational changes. Sickle hemoglobin (HbS) containsa point mutation where glutamic acid is replaced with valine, making HbSsusceptible to polymerization under hypoxic conditions to give the HbScontaining red blood cells their characteristic sickle shape. Thesickled cells are also more rigid than normal red blood cells, and theirlack of flexibility can lead to blockage of blood vessels.

2-hydroxy-6-((2-(1-isopropyl-1H-pyrazol-5-yl)pyridin-3-yl)methoxy)benzaldehyde(also known as voxelotor or GBT440), a modulator of hemoglobin thatincreases the affinity of hemoglobin for oxygen and consequentlyinhibits polymerization of HbS when subjected to hypoxic conditions, iscurrently in Phase 3 clinical trials for the treatment of sickle celldisease (NCT03036813).

WO 2014/150268 describes modulators of hemoglobin that are structurallyrelated to the compounds disclosed herein.

A need exists for compounds that can treat disorders that are mediatedby abnormal Hb such as HbS and methods of treating such disorders.Compounds that have an improved pharmacokinetic profile relative toknown modulators of hemoglobin while maintaining or improving efficacyare of particular interest, as such compounds would allow for favorabledosing regimens (e.g., lower and/or less frequent doses).

SUMMARY

Provided herein is a compound of formula I:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof, wherein:

X is CH or N;

Y is CH or N;

Z is absent, CH₂, O, or S; and

R¹ is mono-hydroxy-(C₁₋₄alkyl), di-hydroxy-(C₁₋₄ alkyl), —CH₂CH₂OCH₃,—CH₂CH₂CN, or

Some embodiments provide for pharmaceutical compositions comprising acompound as described herein, or an isotopically enriched analog,stereoisomer, mixture of stereoisomers, or prodrug thereof, or apharmaceutically acceptable salt of each thereof, and a pharmaceuticallyacceptable excipient. Some embodiments provide for pharmaceuticalcompositions comprising a compound as described herein or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable excipient. Some embodiments provide for pharmaceuticalcompositions comprising a compound as described herein and apharmaceutically acceptable excipient.

Also provided herein are methods for increasing oxygen affinity ofhemoglobin (e.g., hemoglobin S) in a subject in need thereof, comprisingadministering to the subject a compound as described herein or apharmaceutical composition as described herein.

Also provided herein are methods for treating a disorder mediated byhemoglobin in a subject in need thereof, comprising administering to thesubject a compound as described herein or a pharmaceutical compositionas described herein.

Also provided herein are methods for treating sickle cell disease in asubject in need thereof, comprising administering to the subject acompound as described herein or a pharmaceutical composition asdescribed herein.

DETAILED DESCRIPTION Definitions

As used in the present specification, the following words, phrases andsymbols are generally intended to have the meanings as set forth below,except to the extent that the context in which they are used indicatesotherwise.

A dash (“—”) that is not between two letters or symbols is used toindicate a point of attachment for a substituent. For example, —C(O)NH₂is attached through the carbon atom. A dash at the front or end of achemical group is a matter of convenience; chemical groups may bedepicted with or without one or more dashes without losing theirordinary meaning. A wavy line or a dashed line drawn through orperpendicular across the end of a line in a structure indicates aspecified point of attachment of a group. Unless chemically orstructurally required, no directionality or stereochemistry is indicatedor implied by the order in which a chemical group is written or named.

The prefix “C_(u-v)” indicates that the following group has from u to vcarbon atoms. For example, “C₁₋₆ alkyl” indicates that the alkyl grouphas from 1 to 6 carbon atoms. In another example, “C₁₋₄ alkyl” indicatesthat the alkyl group has from 1 to 4 carbon atoms.

Reference to “about” a value or parameter herein includes (anddescribes) embodiments that are directed to that value or parameter perse. In certain embodiments, the term “about” includes the indicatedamount ±10%. In other embodiments, the term “about” includes theindicated amount ±5%. In certain other embodiments, the term “about”includes the indicated amount ±1%. Also, to the term “about x” includesdescription of “x”. Also, the singular forms “a” and “the” includeplural references unless the context clearly dictates otherwise. Thus,e.g., reference to “the compound” includes a plurality of such compoundsand reference to “the assay” includes reference to one or more assaysand equivalents thereof known to those skilled in the art.

“Alkyl” refers to an unbranched or branched saturated hydrocarbon chain.As used herein, alkyl has 1 to 20 carbon atoms (i.e., C₁₋₂₀ alkyl), 1 to12 carbon atoms (i.e., C₁₋₁₂ alkyl), 1 to 8 carbon atoms (i.e., C₁₋₈alkyl), 1 to 6 carbon atoms (i.e., C₁₋₆ alkyl) or 1 to 4 carbon atoms(i.e., C₁₋₄ alkyl). Examples of alkyl groups include, e.g., methyl,ethyl, propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, tert-butyl,pentyl, 2-pentyl, isopentyl, neopentyl, hexyl, 2-hexyl, 3-hexyl and3-methylpentyl. When an alkyl residue having a specific number ofcarbons is named by chemical name or identified by molecular formula,all positional isomers having that number of carbons may be encompassed;thus, for example, “butyl” includes n-butyl (i.e., —(CH₂)₃CH₃),sec-butyl (i.e., —CH(CH₃)CH₂CH₃), isobutyl (i.e., —CH₂CH(CH₃)₂) andtert-butyl (i.e., —C(CH₃)₃); and “propyl” includes n-propyl (i.e.,—(CH₂)₂CH₃) and isopropyl (i.e., —CH(CH₃)₂).

Certain commonly used alternative chemical names may be used. Forexample, a divalent group such as a divalent “alkyl” group, a divalent“aryl” group, etc., may also be referred to as an “alkylene” group or an“alkylenyl” group, an “arylene” group or an “arylenyl” group,respectively. Also, unless indicated explicitly otherwise, wherecombinations of groups are referred to herein as one moiety, e.g.,arylalkyl or aralkyl, the last-mentioned group contains the atom bywhich the moiety is attached to the rest of the molecule.

“Alkenyl” refers to an alkyl group containing at least one carbon-carbondouble bond and having from 2 to 20 carbon atoms (i.e., C₂₋₂₀ alkenyl),2 to 8 carbon atoms (i.e., C₂₋₈ alkenyl), 2 to 6 carbon atoms (i.e.,C₂₋₆ alkenyl) or 2 to 4 carbon atoms (i.e., C₂₋₄ alkenyl). Examples ofalkenyl groups include, e.g., ethenyl, propenyl, butadienyl (including1,2-butadienyl and 1,3-butadienyl).

“Alkynyl” refers to an alkyl group containing at least one carbon-carbontriple bond and having from 2 to 20 carbon atoms (i.e., C₂₋₂₀ alkynyl),2 to 8 carbon atoms (i.e., C2-8 alkynyl), 2 to 6 carbon atoms (i.e.,C₂₋₆ alkynyl) or 2 to 4 carbon atoms (i.e., C₂₋₄ alkynyl). The term“alkynyl” also includes those groups having one triple bond and onedouble bond.

“Alkoxy” refers to the group “alkyl-O—”. Examples of alkoxy groupsinclude, e.g., methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy,tert-butoxy, sec-butoxy, n-pentoxy, n-hexoxy and 1,2-dimethylbutoxy.

“Alkylthio” refers to the group “alkyl-S—”. “Alkylsulfinyl” refers tothe group “alkyl-S(O)—”. “Alkylsulfonyl” refers to the group“alkyl-S(O)₂—”

“Acyl” refers to a group —C(O)R^(y), wherein R^(y) is hydrogen, alkyl,alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroalkyl orheteroaryl; each of which may be optionally substituted, as definedherein. Examples of acyl include, e.g., formyl, acetyl,cyclohexylcarbonyl, cyclohexylmethyl-carbonyl and benzoyl.

“Amido” refers to both a “C-amido” group which refers to the group—C(O)NR^(y)R^(z) and an “N-amido” group which refers to the group—NR^(y)C(O)R^(z), wherein R^(y) and R^(z) are independently hydrogen,alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroalkyl orheteroaryl; each of which may be optionally substituted, as definedherein, or R^(y) and R^(z) are taken together to form a cycloalkyl orheterocyclyl; each of which may be optionally substituted, as definedherein.

“Amino” refers to the group —NR^(y)R^(z) wherein R^(y) and R^(z) areindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,heterocyclyl, aryl, heteroalkyl or heteroaryl; each of which may beoptionally substituted, as defined herein.

“Amidino” refers to —C(NR^(y))(NR^(z) ₂), wherein R^(y) and R^(z) areindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,heterocyclyl, aryl, heteroalkyl or heteroaryl; each of which may beoptionally substituted, as defined herein.

“Aryl” refers to an aromatic carbocyclic group having a single ring(e.g., monocyclic) or multiple rings (e.g., bicyclic or tricyclic)including fused systems. As used herein, aryl has 6 to 20 ring carbonatoms (i.e., C₆₋₂₀ aryl), 6 to 12 carbon ring atoms (i.e., C₆₋₁₂ aryl),or 6 to 10 carbon ring atoms (i.e., C₆₋₁₀ aryl). Examples of aryl groupsinclude, e.g., phenyl, naphthyl, fluorenyl and anthryl. Aryl, however,does not encompass or overlap in any way with heteroaryl defined below.If one or more aryl groups are fused with a heteroaryl, the resultingring system is heteroaryl regardless of the point of attachment. If oneor more aryl groups are fused with a heterocyclyl, the resulting ringsystem is heterocyclyl regardless of the point of attachment.

“Arylalkyl” or “Aralkyl” refers to the group “aryl-alkyl-”.

“Carbamoyl” refers to both an “0-carbamoyl” group which refers to thegroup —O—C(O)NR^(y)R^(z) and an “N-carbamoyl” group which refers to thegroup —NR^(y)C(O)OR^(z), wherein R^(y) and R^(z) are independentlyhydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl,heteroalkyl or heteroaryl; each of which may be optionally substituted,as defined herein.

“Carboxyl ester” or “ester” refer to both —OC(O)R^(x) and —C(O)OR^(x),wherein R^(x) is alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl,aryl, heteroalkyl or heteroaryl; each of which may be optionallysubstituted, as defined herein.

“Cycloalkyl” refers to a saturated or partially unsaturated cyclic alkylgroup having a single ring or multiple rings including fused, bridgedand spiro ring systems. The term “cycloalkyl” includes cycloalkenylgroups (i.e., the cyclic group having at least one double bond) andcarbocyclic fused ring systems having at least one sp³ carbon atom(i.e., at least one non-aromatic ring). As used herein, cycloalkyl hasfrom 3 to 20 ring carbon atoms (i.e., C₃₋₂₀ cycloalkyl), 3 to 12 ringcarbon atoms (i.e., C₃₋₁₂ cycloalkyl), 3 to 10 ring carbon atoms (i.e.,C₃₋₁₀ cycloalkyl), 3 to 8 ring carbon atoms (i.e., C₃₋₈ cycloalkyl), or3 to 6 ring carbon atoms (i.e., C₃₋₆ cycloalkyl). Monocyclic groupsinclude, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cycloheptyl and cyclooctyl. Polycyclic groups include, for example,bicyclo[2.2.1]heptanyl, bicyclo[2.2.2]octanyl, adamantyl, norbornyl,decalinyl, 7,7-dimethyl-bicyclo[2.2.1]heptanyl and the like. Further,the term cycloalkyl is intended to encompass any non-aromatic ring whichmay be fused to an aryl ring, regardless of the attachment to theremainder of the molecule. Still further, cycloalkyl also includes“spirocycloalkyl” when there are two positions for substitution on thesame carbon atom, for example spiro[2.5]octanyl, spiro[4.5]decanyl, orspiro[5.5]undecanyl.

“Cycloalkylalkyl” refers to the group “cycloalkyl-alkyl-”.

“Guanidino” refers to —NR^(y)C(═NR^(z))(NR^(y)R^(z)), wherein each R^(y)and R^(z) are independently hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, heterocyclyl, aryl, heteroalkyl or heteroaryl; each of whichmay be optionally substituted, as defined herein.

“Imino” refers to a group —C(NR^(y))R^(z), wherein R^(y) and R^(z) areeach independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,heterocyclyl, aryl, heteroalkyl or heteroaryl; each of which may beoptionally substituted, as defined herein.

“Imido” refers to a group —C(O)NR^(y)C(O)R^(z), wherein R^(y) and R^(z)are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,heterocyclyl, aryl, heteroalkyl or heteroaryl; each of which may beoptionally substituted, as defined herein.

“Halogen” or “halo” refers to atoms occupying group VIIA of the periodictable, such as fluoro, chloro, bromo or iodo.

“Haloalkyl” refers to an unbranched or branched alkyl group as definedabove, wherein one or more (e.g., 1 to 6, or 1 to 3) hydrogen atoms arereplaced by a halogen. For example, where a residue is substituted withmore than one halogen, it may be referred to by using a prefixcorresponding to the number of halogen moieties attached. Dihaloalkyland trihaloalkyl refer to alkyl substituted with two (“di”) or three(“tri”) halo groups, which may be, but are not necessarily, the samehalogen. Examples of haloalkyl include, e.g., trifluoromethyl,difluoromethyl, fluoromethyl, trichloromethyl, 2,2,2-trifluoroethyl,1,2-difluoroethyl, 3-bromo-2-fluoropropyl, 1,2-dibromoethyl and thelike.

“Haloalkoxy” refers to an alkoxy group as defined above, wherein one ormore (e.g., 1 to 6, or 1 to 3) hydrogen atoms are replaced by a halogen.

“Hydroxyalkyl” refers to an alkyl group as defined above, wherein one ormore (e.g., 1 to 6, or 1 to 3) hydrogen atoms are replaced by a hydroxygroup. A “mono-hydroxy-(C₁₋₄ alkyl)” refers to a C1-4 alkyl group asdefined above, wherein one hydrogen atom is replaced by a hydroxy group.A “di-hydroxy-(C₁₋₄ alkyl)” refers to a C₁₋₄ alkyl group as definedabove, wherein two hydrogen atoms are replaced by hydroxy groups.

“Heteroalkyl” refers to an alkyl group in which one or more of thecarbon atoms (and any associated hydrogen atoms) are each independentlyreplaced with the same or different heteroatomic group, provided thepoint of attachment to the remainder of the molecule is through a carbonatom. The term “heteroalkyl” includes unbranched or branched saturatedchain having carbon and heteroatoms. By way of example, 1, 2 or 3 carbonatoms may be independently replaced with the same or differentheteroatomic group. Heteroatomic groups include, but are not limited to,—NR^(y)—, —O—, —S—, —S(O)—, —S(O)₂—, and the like, wherein RY ishydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl,heteroalkyl or heteroaryl; each of which may be optionally substituted,as defined herein. Examples of heteroalkyl groups include, e.g., ethers(e.g., —CH₂OCH₃, —CH(CH₃)OCH₃, —CH₂CH₂OCH₃, —CH₂CH₂OCH₂CH₂OCH₃, etc.),thioethers (e.g., —CH₂SCH₃, —CH(CH₃)SCH₃, —CH₂CH₂SCH₃,—CH₂CH₂SCH₂CH₂SCH₃, etc.), sulfones (e.g., —CH₂S(O)₂CH₃,—CH(CH₃)S(O)₂CH₃, —CH₂CH₂S(O)₂CH₃, —CH₂CH₂S(O)₂CH₂CH₂OCH₃, etc.) andamines (e.g., —CH₂NR^(y)CH₃, —CH(CH₃)NR^(y)CH₃, —CH₂CH₂NR^(y)CH₃,—CH₂CH₂NR^(y)CH₂CH₂NR^(y)CH₃, etc., where R^(y) is hydrogen, alkyl,alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroalkyl, orheteroaryl; each of which may be optionally substituted, as definedherein). As used herein, heteroalkyl includes 1 to 10 carbon atoms, 1 to8 carbon atoms, or 1 to 4 carbon atoms; and 1 to 3 heteroatoms, 1 to 2heteroatoms, or 1 heteroatom.

“Heteroaryl” refers to an aromatic group having a single ring, multiplerings or multiple fused rings, with one or more ring heteroatomsindependently selected from nitrogen, oxygen, and sulfur. As usedherein, heteroaryl includes 1 to 20 ring carbon atoms (i.e., C₁₋₂₀heteroaryl), 3 to 12 ring carbon atoms (i.e., C₃₋₁₂ heteroaryl), or 3 to8 carbon ring atoms (i.e., C₃₋₈ heteroaryl), and 1 to 5 ringheteroatoms, 1 to 4 ring heteroatoms, 1 to 3 ring heteroatoms, 1 to 2ring heteroatoms, or 1 ring heteroatom independently selected fromnitrogen, oxygen and sulfur. In certain instances, heteroaryl includes5-10 membered ring systems, 5-7 membered ring systems, or 5-6 memberedring systems, each independently having 1 to 4 ring heteroatoms, 1 to 3ring heteroatoms, 1 to 2 ring heteroatoms, or 1 ring heteroatomindependently selected from nitrogen, oxygen and sulfur. Examples ofheteroaryl groups include, e.g., acridinyl, benzimidazolyl,benzothiazolyl, benzindolyl, benzofuranyl, benzothiazolyl,benzothiadiazolyl, benzonaphthofuranyl, benzoxazolyl, benzothienyl(benzothiophenyl), benzotriazolyl, benzo[4,6]imidazo[1,2-a]pyridyl,carbazolyl, cinnolinyl, dibenzofuranyl, dibenzothiophenyl, furanyl,isothiazolyl, imidazolyl, indazolyl, indolyl, indazolyl, isoindolyl,isoquinolyl, isoxazolyl, naphthyridinyl, oxadiazolyl, oxazolyl,1-oxidopyridinyl, 1-oxidopyrimidinyl, 1-oxidopyrazinyl,1-oxidopyridazinyl, phenazinyl, phthalazinyl, pteridinyl, purinyl,pyrrolyl, pyrazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl,quinazolinyl, quinoxalinyl, quinolinyl, quinuclidinyl, isoquinolinyl,thiazolyl, thiadiazolyl, triazolyl, tetrazolyl and triazinyl. Examplesof the fused-heteroaryl rings include, but are not limited to,benzo[d]thiazolyl, quinolinyl, isoquinolinyl, benzo[b]thiophenyl,indazolyl, benzo[d]imidazolyl, pyrazolo[1,5-a]pyridinyl andimidazo[1,5-a]pyridinyl, where the heteroaryl can be bound via eitherring of the fused system. Any aromatic ring, having a single or multiplefused rings, containing at least one heteroatom, is considered aheteroaryl regardless of the attachment to the remainder of the molecule(i.e., through any one of the fused rings). Heteroaryl does notencompass or overlap with aryl as defined above.

“Heteroarylalkyl” refers to the group “heteroaryl-alkyl-”.

“Heterocyclyl” refers to a saturated or partially unsaturated cyclicalkyl group, with one or more ring heteroatoms independently selectedfrom nitrogen, oxygen and sulfur. The term “heterocyclyl” includesheterocycloalkenyl groups (i.e., the heterocyclyl group having at leastone double bond), bridged-heterocyclyl groups, fused-heterocyclyl groupsand spiro-heterocyclyl groups. A heterocyclyl may be a single ring ormultiple rings wherein the multiple rings may be fused, bridged orspiro, and may comprise one or more (e.g., 1 to 3) oxo (═O) or N-oxide(—O⁻) moieties. Any non-aromatic ring containing at least one heteroatomis considered a heterocyclyl, regardless of the attachment (i.e., can bebound through a carbon atom or a heteroatom). Further, the termheterocyclyl is intended to encompass any non-aromatic ring containingat least one heteroatom, which ring may be fused to an aryl orheteroaryl ring, regardless of the attachment to the remainder of themolecule. As used herein, heterocyclyl has 2 to 20 ring carbon atoms(i.e., C₂₋₂₀ heterocyclyl), 2 to 12 ring carbon atoms (i.e., C₂₋₁₂heterocyclyl), 2 to 10 ring carbon atoms (i.e., C₂₋₁₀ heterocyclyl), 2to 8 ring carbon atoms (i.e., C₂₋₈ heterocyclyl), 3 to 12 ring carbonatoms (i.e., C₃₋₁₂ heterocyclyl), 3 to 8 ring carbon atoms (i.e., C₃₋₈heterocyclyl), or 3 to 6 ring carbon atoms (i.e., C₃₋₆ heterocyclyl);having 1 to 5 ring heteroatoms, 1 to 4 ring heteroatoms, 1 to 3 ringheteroatoms, 1 to 2 ring heteroatoms, or 1 ring heteroatom independentlyselected from nitrogen, sulfur or oxygen. Examples of heterocyclylgroups include, e.g., azetidinyl, azepinyl, benzodioxolyl,benzo[b][1,4]dioxepinyl, 1,4-benzodioxanyl, benzopyranyl, benzodioxinyl,benzopyranonyl, benzofuranonyl, dioxolanyl, dihydropyranyl,hydropyranyl, thienyl[1,3]dithianyl, decahydroisoquinolyl, furanonyl,imidazolinyl, imidazolidinyl, indolinyl, indolizinyl, isoindolinyl,isothiazolidinyl, isoxazolidinyl, morpholinyl, octahydroindolyl,octahydroisoindolyl, 2-oxopiperazinyl, 2-oxopiperidinyl,2-oxopyrrolidinyl, oxazolidinyl, oxiranyl, oxetanyl, phenothiazinyl,phenoxazinyl, piperidinyl, piperazinyl, 4-piperidonyl, pyrrolidinyl,pyrazolidinyl, quinuclidinyl, thiazolidinyl, tetrahydrofuryl,tetrahydropyranyl, trithianyl, tetrahydroquinolinyl, thiophenyl (i.e.,thienyl), tetrahydropyranyl, thiomorpholinyl, thiamorpholinyl,1-oxo-thiomorpholinyl and 1,1-dioxo-thiomorpholinyl. The term“heterocyclyl” also includes “spiroheterocyclyl” when there are twopositions for substitution on the same carbon atom. Examples of thespiro-heterocyclyl rings include, e.g., bicyclic and tricyclic ringsystems, such as 2-oxa-7-azaspiro[3.5]nonanyl,2-oxa-6-azaspiro[3.4]octanyl and 6-oxa-1-azaspiro[3.3]heptanyl. Examplesof the fused-heterocyclyl rings include, but are not limited to,1,2,3,4-tetrahydroisoquinolinyl,4,5,6,7-tetrahydrothieno[2,3-c]pyridinyl, indolinyl and isoindolinyl,where the heterocyclyl can be bound via either ring of the fused system.

“Heterocyclylalkyl” refers to the group “heterocyclyl-alkyl-.”

“Oxime” refers to the group —CR^(y)(═NOH) wherein R^(y) is hydrogen,alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroalkyl orheteroaryl; each of which may be optionally substituted, as definedherein.

“Sulfonyl” refers to the group —S(O)₂R^(y), where R^(y) is hydrogen,alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroalkyl orheteroaryl; each of which may be optionally substituted, as definedherein. Examples of sulfonyl are methylsulfonyl, ethylsulfonyl,phenylsulfonyl and toluenesulfonyl.

“Sulfinyl” refers to the group —S(O)R^(y), where R^(y) is hydrogen,alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroalkyl orheteroaryl; each of which may be optionally substituted, as definedherein. Examples of sulfinyl are methylsulfinyl, ethylsulfinyl,phenylsulfinyl and toluenesulfinyl.

“Sulfonamido” refers to the groups —SO₂NR^(y)R^(z) and —NR^(y)SO₂R^(z),where R^(y) and R^(z) are each independently hydrogen, alkyl, alkenyl,alkynyl, cycloalkyl, heterocyclyl, aryl, heteroalkyl or heteroaryl; eachof which may be optionally substituted, as defined herein.

The terms “optional” or “optionally” means that the subsequentlydescribed event or circumstance may or may not occur and that thedescription includes instances where said event or circumstance occursand instances in which it does not. Also, the term “optionallysubstituted” refers to any one or more (e.g., 1 to 5, or 1 to 3)hydrogen atoms on the designated atom or group may or may not bereplaced by a moiety other than hydrogen.

The term “substituted” used herein means any of the above groups (i.e.,alkyl, alkenyl, alkynyl, alkylene, alkoxy, haloalkyl, haloalkoxy,cycloalkyl, aryl, heterocyclyl, heteroaryl, and/or heteroalkyl) whereinat least one (e.g., 1 to 5, or 1 to 3) hydrogen atom is replaced by abond to a non-hydrogen atom such as, but not limited to alkyl, alkenyl,alkynyl, alkoxy, alkylthio, acyl, amido, amino, amidino, aryl, aralkyl,azido, carbamoyl, carboxyl, carboxyl ester, cyano, cycloalkyl,cycloalkylalkyl, guanidino, halo, haloalkyl, haloalkoxy, hydroxyalkyl,heteroalkyl, heteroaryl, heteroarylalkyl, heterocyclyl,heterocyclylalkyl, —NHNH₂, ═NNH₂, imino, imido, hydroxy, oxo, oxime,nitro, sulfonyl, sulfinyl, alkylsulfonyl, alkylsulfinyl, thiocyanate,—S(O)OH, —S(O)₂OH, sulfonamido, thiol, thioxo, N-oxide or —Si(R^(y))₃,wherein each R^(y) is independently hydrogen, alkyl, alkenyl, alkynyl,heteroalkyl, cycloalkyl, aryl, heteroaryl or heterocyclyl.

In certain embodiments, “substituted” includes any of the above alkyl,alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl or heteroaryl groups inwhich one or more (e.g., 1 to 5, or 1 to 3) hydrogen atoms areindependently replaced with deuterium, halo, cyano, nitro, azido, oxo,alkyl, alkenyl, alkynyl, haloalkyl, cycloalkyl, heterocyclyl, aryl,heteroaryl, —NR^(g)R^(h), —NR^(g)C(═O)R^(h), —NR^(g)C(═O)NR^(g)R^(h),—NR^(g)C(═O)OR^(h), —NR^(g)S(═O)₁₋₂R^(h), —C(═O)R^(g), —C(═O)OR^(g),—OC(═O)OR^(g), —OC(═O)R^(g), —C(═O)NR^(g)R^(h), —OC(═O)NR^(g)R^(h),—OR^(g), —SR^(g), —S(═O)R^(g), —S(═O)₂R^(g), —OS(═O)₁₋₂R^(g),—S(═O)₁₋₂OR^(g), —NR^(g)S(═O)₁₋₂NR^(g)R^(h), ═NSO₂R^(g), ═NOR^(g),—S(═O)₁₋₂NR^(g)R^(h), —SF₅, —SCF₃ or —OCF₃. In certain embodiments,“substituted” also means any of the above ^(g)roups in which one or more(e.g., 1 to 5, or 1 to 3) hydrogen atoms are replaced with —C(═O)R^(g),—C(═O)OR^(g), —C(═O)NR^(g)R^(h), —CH₂SO₂R^(g), or −CH₂SO₂NR^(g)R^(h). Inthe foregoing, R^(g) and R^(h) are the same or different andindependently hydrogen, alkyl, alkenyl, alkynyl, alkoxy, thioalkyl,aryl, aralkyl, cycloalkyl, cycloalkylalkyl, haloalkyl, heterocyclyl,heterocyclylalkyl, heteroaryl, and/or heteroarylalkyl. In certainembodiments, “substituted” also means any of the above groups in whichone or more (e.g., 1 to 5, or 1 to 3) hydrogen atoms are replaced by abond to an amino, cyano, hydroxyl, imino, nitro, oxo, thioxo, halo,alkyl, alkoxy, alkylamino, thioalkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, haloalkyl, heterocyclyl, N-heterocyclyl,heterocyclylalkyl, heteroaryl, and/or heteroarylalkyl, or two of R^(g)and R^(h) and R^(i) are taken together with the atoms to which they areattached to form a heterocyclyl ring optionally substituted with oxo,halo or alkyl optionally substituted with oxo, halo, amino, hydroxyl, oralkoxy.

Polymers or similar indefinite structures arrived at by definingsubstituents with further substituents appended ad infinitum (e.g., asubstituted aryl having a substituted alkyl which is itself substitutedwith a substituted aryl group, which is further substituted by asubstituted heteroalkyl group, etc.) are not intended for inclusionherein. Unless otherwise noted, the maximum number of serialsubstitutions in compounds described herein is three. For example,serial substitutions of substituted aryl groups with two othersubstituted aryl groups are limited to ((substituted aryl)substitutedaryl) substituted aryl. Similarly, the above definitions are notintended to include impermissible substitution patterns (e.g., methylsubstituted with 5 fluorines or heteroaryl groups having two adjacentoxygen ring atoms). Such impermissible substitution patterns are wellknown to the skilled artisan. When used to modify a chemical group, theterm “substituted” may describe other chemical groups defined herein.

In certain embodiments, as used herein, the phrase “one or more” refersto one to five. In certain embodiments, as used herein, the phrase “oneor more” refers to one to three.

Any compound or structure given herein, is intended to representunlabeled forms as well as isotopically labeled forms (isotopologues) ofthe compounds. These forms of compounds may also be referred to as andinclude “isotopically enriched analogs.” Isotopically labeled compoundshave structures depicted herein, except that one or more atoms arereplaced by an atom having a selected atomic mass or mass number.Examples of isotopes that can be incorporated into the disclosedcompounds include isotopes of hydrogen, carbon, nitrogen, oxygen,phosphorous, fluorine, chlorine and iodine, such as ²H, ³H, ¹¹C, ¹³C,¹⁴C, ¹³N, ¹⁵N, ¹⁵O, ¹⁷O, ¹⁸O, ³¹P, ³²P, ³⁵S, ¹⁸F, ³⁶Cl, ¹²³I, and ¹²⁵I,respectively. Various isotopically labeled compounds of the presentdisclosure, for example those into which radioactive isotopes such as³H, ¹³C and ¹⁴C are incorporated. Such isotopically labelled compoundsmay be useful in metabolic studies, reaction kinetic studies, detectionor imaging techniques, such as positron emission tomography (PET) orsingle-photon emission computed tomography (SPECT) including drug orsubstrate tissue distribution assays or in radioactive treatment ofpatients.

The term “isotopically enriched analogs” includes “deuterated analogs”of compounds described herein in which one or more hydrogens is/arereplaced by deuterium, such as a hydrogen on a carbon atom. Suchcompounds exhibit increased resistance to metabolism and are thus usefulfor increasing the half-life of any compound when administered to amammal, particularly a human. See, for example, Foster, “DeuteriumIsotope Effects in Studies of Drug Metabolism,” Trends Pharmacol. Sci.5(12):524-527 (1984). Such compounds are synthesized by means well knownin the art, for example by employing starting materials in which one ormore hydrogens have been replaced by deuterium.

Deuterium labelled or substituted therapeutic compounds of thedisclosure may have improved DMPK (drug metabolism and pharmacokinetics)properties, relating to distribution, metabolism and excretion (ADME).Substitution with heavier isotopes such as deuterium may afford certaintherapeutic advantages resulting from greater metabolic stability, forexample increased in vivo half-life, reduced dosage requirements and/oran improvement in therapeutic index. An ¹⁸F, ³H, ¹¹C labeled compoundmay be useful for PET or SPECT or other imaging studies. Isotopicallylabeled compounds of this disclosure and prodrugs thereof can generallybe prepared by carrying out the procedures disclosed in the schemes orin the examples and preparations described below by substituting areadily available isotopically labeled reagent for a non-isotopicallylabeled reagent. It is understood that deuterium in this context isregarded as a substituent in a compound described herein.

The concentration of such a heavier isotope, specifically deuterium, maybe defined by an isotopic enrichment factor. In the compounds of thisdisclosure any atom not specifically designated as a particular isotopeis meant to represent any stable isotope of that atom. Unless otherwisestated, when a position is designated specifically as “H” or “hydrogen”,the position is understood to have hydrogen at its natural abundanceisotopic composition. Accordingly, in the compounds of this disclosureany atom specifically designated as a deuterium (D) is meant torepresent deuterium. Further, in some embodiments, the correspondingdeuterated analog is provided.

In many cases, the compounds of this disclosure are capable of formingacid and/or base salts by virtue of the presence of amino and/orcarboxyl groups or groups similar thereto.

Provided also are a pharmaceutically acceptable salt, isotopicallyenriched analog, deuterated analog, isomer (such as a stereoisomer),mixture of isomers (such as a mixture of stereoisomers), prodrug, andmetabolite of the compounds described herein.

“Pharmaceutically acceptable” or “physiologically acceptable” refer tocompounds, salts, compositions, dosage forms and other materials whichare useful in preparing a pharmaceutical composition that is suitablefor veterinary or human pharmaceutical use.

The term “pharmaceutically acceptable salt” of a given compound refersto salts that retain the biological effectiveness and properties of thegiven compound and which are not biologically or otherwise undesirable.“Pharmaceutically acceptable salts” or “physiologically acceptablesalts” include, for example, salts with inorganic acids and salts withan organic acid. In addition, if the compounds described herein areobtained as an acid addition salt, the free base can be obtained bybasifying a solution of the acid salt. Conversely, if the product is afree base, an addition salt, particularly a pharmaceutically acceptableaddition salt, may be produced by dissolving the free base in a suitableorganic solvent and treating the solution with an acid, in accordancewith conventional procedures for preparing acid addition salts from basecompounds. Those skilled in the art will recognize various syntheticmethodologies that may be used to prepare nontoxic pharmaceuticallyacceptable addition salts. Pharmaceutically acceptable acid additionsalts may be prepared from inorganic and organic acids. Salts derivedfrom inorganic acids include, e.g., hydrochloric acid, hydrobromic acid,sulfuric acid, nitric acid, phosphoric acid and the like. Salts derivedfrom organic acids include, e.g., acetic acid, propionic acid, gluconicacid, glycolic acid, pyruvic acid, oxalic acid, malic acid, malonicacid, succinic acid, maleic acid, fumaric acid, tartaric acid, citricacid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid,ethanesulfonic acid, p-toluene-sulfonic acid, salicylic acid and thelike. Likewise, pharmaceutically acceptable base addition salts can beprepared from inorganic and organic bases. Salts derived from inorganicbases include, by way of example only, sodium, potassium, lithium,aluminum, ammonium, calcium and magnesium salts. Salts derived fromorganic bases include, but are not limited to, salts of primary,secondary and tertiary amines, such as alkyl amines (i.e., NH₂(alkyl)),dialkyl amines (i.e., HN(alkyl)₂), trialkyl amines (i.e., N(alkyl)₃),substituted alkyl amines (i.e., NH₂(substituted alkyl)), di(substitutedalkyl) amines (i.e., HN(substituted alkyl)₂), tri(substituted alkyl)amines (i.e., N(substituted alkyl)₃), alkenyl amines (i.e.,NH₂(alkenyl)), dialkenyl amines (i.e., HN(alkenyl)₂), trialkenyl amines(i.e., N(alkenyl)₃), substituted alkenyl amines (i.e., NH₂(substitutedalkenyl)), di(substituted alkenyl) amines (i.e., HN(substitutedalkenyl)2), tri(substituted alkenyl) amines (i.e., N(substitutedalkenyl)₃, mono-, di- or tri-cycloalkyl amines (i.e., NH₂(cycloalkyl),HN(cycloalkyl)₂, N(cycloalkyl)₃), mono-, di- or tri-arylamines (i.e.,NH₂(aryl), HN(aryl)₂, N(aryl)₃) or mixed amines, etc. Specific examplesof suitable amines include, by way of example only, isopropylamine,trimethyl amine, diethyl amine, tri(iso-propyl) amine, tri(n-propyl)amine, ethanolamine, 2-dimethylaminoethanol, piperazine, piperidine,morpholine, N-ethylpiperidine and the like. In some embodiments, apharmaceutically acceptable salt does not include a salt of a primaryamine.

The term “hydrate” refers to the complex formed by the combining of acompound described herein and water.

A “solvate” refers to an association or complex of one or more solventmolecules and a compound of the disclosure. Examples of solvents thatform solvates include, but are not limited to, water, isopropanol,ethanol, methanol, dimethylsulfoxide, ethylacetate, acetic acid andethanolamine

Some of the compounds exist as tautomers. Tautomers are in equilibriumwith one another. For example, amide containing compounds may exist inequilibrium with imidic acid tautomers. Regardless of which tautomer isshown and regardless of the nature of the equilibrium among tautomers,the compounds are understood by one of ordinary skill in the art tocomprise both amide and imidic acid tautomers. Thus, the amidecontaining compounds are understood to include their imidic acidtautomers. Likewise, the imidic acid containing compounds are understoodto include their amide tautomers.

The compounds of the invention, or their pharmaceutically acceptablesalts include an asymmetric center and may thus give rise toenantiomers, diastereomers, and other stereoisomeric forms that may bedefined, in terms of absolute stereochemistry, as (R)- or (S)- or, as(D)- or (L)- for amino acids. The present invention is meant to includeall such possible isomers, as well as their racemic and optically pureforms. Optically active (+) and (−), (R)- and (S)-, or (D)- and(L)-isomers may be prepared using chiral synthons or chiral reagents, orresolved using conventional techniques, for example, chromatography andfractional crystallization. Conventional techniques for thepreparation/isolation of individual enantiomers include chiral synthesisfrom a suitable optically pure precursor or resolution of the racemate(or the racemate of a salt or derivative) using, for example, chiralhigh performance liquid chromatography (HPLC). When the compoundsdescribed herein contain olefinic double bonds or other centres ofgeometric asymmetry, and unless specified otherwise, it is intended thatthe compounds include both E and Z geometric isomers.

A “stereoisomer” refers to a compound made up of the same atoms bondedby the same bonds but having different three-dimensional structures,which are not interchangeable. The present invention contemplatesvarious stereoisomers and mixtures thereof and includes “enantiomers,”which refers to two stereoisomers whose molecules are nonsuperimposeablemirror images of one another.

“Diastereomers” are stereoisomers that have at least two asymmetricatoms, but which are not mirror-images of each other.

Relative centers of the compounds as depicted herein are indicatedgraphically using the “thick bond” style (bold or parallel lines) andabsolute stereochemistry is depicted using wedge bonds (bold or parallellines).

“Prodrugs” means any compound which releases an active parent drugaccording to a structure described herein in vivo when such prodrug isadministered to a mammalian subject. Prodrugs of a compound describedherein are prepared by modifying functional groups present in thecompound described herein in such a way that the modifications may becleaved in vivo to release the parent compound. Prodrugs may be preparedby modifying functional groups present in the compounds in such a waythat the modifications are cleaved, either in routine manipulation or invivo, to the parent compounds. Prodrugs include compounds describedherein wherein a hydroxy, amino, carboxyl, or sulfhydryl group in acompound described herein is bonded to any group that may be cleaved invivo to regenerate the free hydroxy, amino, or sulfhydryl group,respectively. Examples of prodrugs include, but are not limited toesters (e.g., acetate, formate and benzoate derivatives), amides,guanidines, carbamates (e.g., N,N-dimethylaminocarbonyl) of hydroxyfunctional groups in compounds described herein and the like.Preparation, selection and use of prodrugs is discussed in T. Higuchiand V. Stella, “Pro-drugs as Novel Delivery Systems,” Vol. 14 of theA.C.S. Symposium Series; “Design of Prodrugs,” ed. H. Bundgaard,Elsevier, 1985; and in Bioreversible Carriers in Drug Design, ed. EdwardB. Roche, American Pharmaceutical Association and Pergamon Press, 1987,each of which are hereby incorporated by reference in their entirety.

The term, “metabolite,” as used herein refers to a resulting productformed when a compound disclosed herein is metabolized. As used herein,the term “metabolized” refers to the sum of processes (including but notlimited to hydrolysis reactions and reactions catalyzed by enzymes) bywhich a particular substance, such as a compound disclosed herein, ischanged by an organism. For example, an aldehyde moiety (—C(O)H) of thecompounds of the invention may be reduced in vivo to a —CH₂OH moiety.

The term “hydroxy protecting group” refers to a chemical moiety which isadded to, and later removed from, a hydroxy functionality to obtainchemoselectivity in a subsequent chemical reaction. Exemplary protectinggroups, as well as the methods for deprotection, include, but are notlimited to, acetyl (Ac) (removed by acid or base), benzoyl (Bz) (removedby acid or base), benzyl (Bn) (removed by hydrogenolysis),β-methoxyethoxymethyl ether (MEM) (removed by acid), dimethoxytrityl or[bis-(4-methoxyphenyl)phenylmethyl] (DMT) (removed by weak acid),methoxymethyl ether (MOM) (removed by acid), methoxytrityl or[(4-methoxyphenyl)diphenylmethyl] (MMT) (removed by acid andhydrogenolysis), p-methoxybenzyl ether (PMB) (removed by acid,hydrogenolysis, or oxidation), methylthiomethyl ether (removed by acid),pivaloyl (Piv) (removed by acid, base or reductant agents),tetrahydropyranyl (THP) (removed by acid), tetrahydrofuran (THF)(removed by acid), trityl (triphenylmethyl, Tr) (removed by acid andhydrogenolysis), silyl ether (e.g., trimethylsilyl (TMS),tert-butyldimethylsilyl (TBDMS), tri-iso-propylsilyloxymethyl (TOM), andtriisopropylsilyl (TIPS) ethers) (removed by acid or fluoride ion, suchas NaF, TBAF (tetra-n-butylammonium fluoride, HF-Py, or HF-NEt3)),methyl ethers (removed by cleavage is by TMSI in dichloromethane oracetonitrile or chloroform, or BBr3 in DCM), ethoxyethyl ethers (EE)(removed by 1N hydrochloric acid).

Compounds

Provided herein are compounds that are useful as modulators ofhemoglobin. It is contemplated that compounds disclosed herein have animproved pharmacokinetic profile relative to known modulators ofhemoglobin while maintaining or improving efficacy. It is furthercontemplated that compounds disclosed herein have an improved safetypharmacological profile relative to known modulators of hemoglobin.

Provided herein is a compound of formula I:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof, wherein X, Y, Z, and R¹ are as defined herein.

In some embodiments, X is CH or N. In some embodiments, X is CH. In someembodiments, X is N.

In some embodiments, Y is CH or N. In some embodiments, Y is CH. In someembodiments, Y is N.

In some embodiments, X is CH or N; and Y is CH. In some embodiments, Xis CH; and Y is CH. In some embodiments, X is N; and Y is CH. In someembodiments, X is CH; and Y is N. In some embodiments, X is N; and Y isN.

In some embodiments, Z is absent, CH₂, O, or S. In some embodiments, Zis CH₂, O, or S. In some embodiments, Z is O or S. In some embodiments,Z is absent, CH₂, or O. In some embodiments, Z is absent. In someembodiments, Z is CH₂. In some embodiments, Z is O. In some embodiments,Z is S.

In some embodiments, R¹ is mono-hydroxy-(C₁₋₄ alkyl), di-hydroxy-(C₁₋₄alkyl), —CH₂CH₂OCH₃, —CH₂CH₂CN, or

In some embodiments, R¹ is mono-hydroxy-(C₁₋₄ alkyl), di-hydroxy-(C₁₋₄alkyl), —CH₂CH₂CN, or

In some embodiments, R¹ is mono-hydroxy-(C₁₋₄ alkyl), di-hydroxy-(C₁₋₄alkyl), —CH₂CH₂OCH₃, or —CH₂CH₂CN. In some embodiments, R¹ ismono-hydroxy-(C₁₋₄ alkyl), di-hydroxy-(C₁₋₄ alkyl), or —CH2CH2CN.

In some embodiments, R¹ is —CH₂OH, —CH₂CH₂OH, —CH₂CH₂OCH₃, —CH₂CH₂CN, or

In some embodiments, R¹ is —CH₂OH, —CH₂CH₂OH, —CH₂CH₂CN, or

In some embodiments, R¹ is —CH₂OH, —CH₂CH₂OH, —CH₂CH₂OCH₃, or —CH₂CH₂CN.In some embodiments, R¹ is —CH₂OH, —CH₂CH₂OH, or —CH₂CH₂CN. In someembodiments, R¹ is —CH₂OH or —CH₂CH₂OH. In some embodiments, R¹ is—CH₂OH. In some embodiments, R¹ is —CH₂CH₂OH. In some embodiments, R¹ is—CH₂CH₂OCH₃. In some embodiments, R¹ is —CH₂CH₂CN. In some embodiments,R¹ is

In some embodiments, R¹ is mono-hydroxy-(C₁₋₄ alkyl) or di-hydroxy-(C₁₋₄alkyl). In some embodiments, R¹ is mono-hydroxy-(C₁₋₄ alkyl). In someembodiments, R¹ is di-hydroxy-(C₂₋₄ alkyl). In some embodiments, R¹ ismono-hydroxy-(C₁₋₃ alkyl) or di-hydroxy-(C₁₋₃ alkyl). In someembodiments, R¹ is mono-hydroxy-(C₁₋₃ alkyl). In some embodiments, R¹ isdi-hydroxy-(C₂₋₃ alkyl). In some embodiments, R¹ is mono-hydroxy-(C₁₋₃alkyl) or di-hydroxy-(C₁₋₂ alkyl).

In some embodiments, R¹ is hydroxymethyl, 1-hydroxyethyl,2-hydroxyethyl, 1,2-dihydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, or2-hydroxy-2-methylpropyl. In some embodiments, R¹ is hydroxymethyl,1-hydroxyethyl, 2-hydroxyethyl, 1,2-dihydroxyethyl, or 2-hydroxypropyl.In some embodiments, R¹ is hydroxymethyl, 1-hydroxyethyl,2-hydroxyethyl, or 2-hydroxypropyl.

In some embodiments, R¹ is hydroxymethyl (i.e., —CH₂OH) or2-hydroxyethyl (i.e., —CH₂CH₂OH). In some embodiments, R¹ ishydroxymethyl.

In some embodiments, R¹ is 1-hydroxyethyl or 2-hydroxyethyl. In someembodiments, R¹ is 1-hydroxyethyl. In some embodiments, R¹ is

In some embodiments, R¹ is

In some embodiments, R¹ is 2-hydroxyethyl. In some embodiments, R^(i) is1,2-dihydroxyethyl. In some embodiments, R¹ is

In some embodiments, R¹ is

In some embodiments, R¹ is 2-hydroxypropyl. In some embodiments, R¹ is

In some embodiments, R¹ is

In some embodiments, R¹ is 3-hydroxypropyl.

In some embodiments, R¹ is 2-hydroxy-2-methylpropyl.

In some embodiments, R¹ is

wherein R^(1a) is hydrogen or methyl; R^(1b) is hydrogen or methyl; andR^(1c) is hydrogen or hydroxy.

Any of the combinations of X, Y, Z, and R¹ are encompassed and providedby this disclosure.

Some embodiments provide for a compound of formula I:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof, wherein:

X is CH or N;

Y is CH or N;

Z is absent, CH₂, O, or S; and

R¹ is —CH₂OH, —CH₂CH₂OH, —CH₂CH₂OCH₃, —CH₂CH₂CN, or

Some embodiments provide for a compound of formula I:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof, wherein:

X is CH or N;

Y is CH or N;

Z is absent, CH₂, or O; and

R¹ is —CH₂OH, —CH₂CH₂OH, —CH₂CH₂OCH₃, —CH₂CH₂CN, or

In some embodiments, Y is CH; and Z is CH₂.

Some embodiments provide for a compound of formula Ia:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof, wherein:

X is CH or N; and

R¹ is —CH₂OH, —CH₂CH₂OH, —CH₂CH₂OCH₃, —CH₂CH₂CN, or

In some embodiments, X is CH or N; Y is CH; Z is CH₂, O, or S; and R¹ isa mono-hydroxy-(C₁₋₄ alkyl) or di-hydroxy-(C₁₋₄ alkyl) moiety asdescribed herein.

In some embodiments, X is CH or N; Y is CH; Z is CH₂, O, or S; and R¹ isa mono-hydroxy-(C₁₋₄ alkyl) moiety as described herein.

In some embodiments, X is N; Y is CH; Z is CH₂, O, or S; and R¹ is amono-hydroxy-(C₁₋₄ alkyl) moiety as described herein.

In some embodiments, X is N; Y is CH; Z is 0 or S; and R¹ ismono-hydroxy-(C₁₋₄ alkyl) moiety as described herein.

In some embodiments, X is N; Y is CH; Z is CH₂, O, or S; and R¹ is—CH₂OH or —CH₂CH₂OH. In some embodiments, X is N; Y is CH; Z is O or S;and R¹ is —CH₂OH or —CH₂CH₂OH. In some embodiments, X is N; Y is CH; Zis CH₂; and R¹ is —CH₂OH or —CH₂CH₂OH. In some embodiments, X is N; Y isCH; Z is O; and R¹ is —CH₂OH or —CH₂CH₂OH. In some embodiments, X is N;Y is CH; Z is S; and R¹ is —CH₂OH or —CH₂CH₂OH.

Some embodiments provide for a compound of formula Ib:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof, wherein:

Z is CH₂, O, or S; and

R¹ is a mono-hydroxy-(C₁₋₄ alkyl) moiety as described herein.

In some embodiments, X is CH or N; Y is CH; Z is CH₂, O, or S; and R¹ isa di-hydroxy-(C₂₋₄ alkyl) moiety as described herein. In someembodiments, X is CH; Y is CH; Z is CH₂, O, or S; and R¹ is adi-hydroxy-(C₂₋₄ alkyl) moiety as described herein. In some embodiments,X is CH; Y is CH; Z is O or S; and R¹ is a di-hydroxy-(C₂₋₄ alkyl)moiety as described herein. In some embodiments, X is CH; Y is CH; Z isCH₂; and R¹ is a di-hydroxy-(C₂₋₄ alkyl) moiety as described herein. Insome embodiments, X is CH; Y is CH; Z is O; and R¹ is a di-hydroxy-(C₂₋₄alkyl) moiety as described herein. In some embodiments, X is CH; Y isCH; Z is S; and R¹ is di-hydroxy-(C₂₋₄ alkyl) moiety as describedherein.

Some embodiments provide for a compound of formula Ic:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof, wherein:

Z is CH₂, O, or S; and

R¹ is a di-hydroxy-(C₁₋₄ alkyl) moiety as described herein.

Provided herein is a compound of formula:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof.

Provided herein is a compound of formula:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof.

Provided herein is a compound of formula:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof.

Provided herein is a compound of formula:

or an isotopically enriched analog, stereoisomer, mixture ofstereoisomers, or prodrug thereof, or a pharmaceutically acceptable saltof each thereof.

Provided herein is a compound of formula:

or a pharmaceutically acceptable salt of each thereof.

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

In some embodiments, the compound is:

or a pharmaceutically acceptable salt thereof.

In some embodiments, the compound is:

Provided herein is a compound selected from Table 1, or an isotopicallyenriched analog, stereoisomer, mixture of stereoisomers, or prodrugthereof, or a pharmaceutically acceptable salt of each thereof. Providedherein is a compound selected from Table 1, or a pharmaceuticallyacceptable salt thereof. Provided herein is a compound selected fromTable 1.

Provided herein is a compound selected from Table 2, or an isotopicallyenriched analog, stereoisomer, mixture of stereoisomers, or prodrugthereof, or a pharmaceutically acceptable salt of each thereof. Providedherein is a compound selected from Table 2, or a pharmaceuticallyacceptable salt thereof. Provided herein is a compound selected fromTable 2.

Compound numbers and IUPAC names of compounds described herein aresummarized in Table 1 and Table 2.

TABLE 1 Compound Number Structure IUPAC name 1

(S)-2-hydroxy-6-((1-(2-(2- hydroxyethyl)nicotinoyl)-piperidin-2-yl)methoxy)- benzaldehyde 2

(S)-2-hydroxy-6-((1-(2-(2- methoxyethyl)nicotinoyl)-piperidin-2-yl)methoxy)- benzaldehyde 3

(S)-3-(3-(2-((2-formyl-3- hydroxyphenoxy)methyl)-piperidine-1-carbonyl)- pyridin-2-yl)propanenitrile 4

(S)-2-hydroxy-6-((1-(2-(2- (pyrrolidin-1-yl)ethyl)-nicotinoyl)piperidin-2- yl)methoxy)benzaldehyde 5

(S)-2-hydroxy-6-((1-(2- (hydroxymethyl)benzoyl)-piperidin-2-yl)methoxy)- benzaldehyde 6

(S)-2-hydroxy-6-((1-(2-(2- hydroxyethyl)benzoyl)-piperidin-2-yl)methoxy)- benzaldehyde 7

(S)-2-hydroxy-6-((1-(3- (2-hydroxyethyl)pyrazine-2-carbonyl)piperidin-2- yl)methoxy)benzaldehyde 8

(S)-2-hydroxy-6-((4-(2- (2-hydroxyethyl)- nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde 9

(S)-2-hydroxy-6-((1-(2- (2-hydroxyethyl)- nicotinoyl)pyrrolidin-2-yl)methoxy)benzaldehyde 10 (Enantiomer 2)

2-hydroxy-6-((4-(2-(2- hydroxyethyl)nicotinoyl)- thiomorpholin-3-yl)-methoxy)benzaldehyde 10 (Enantiomer 1)

2-hydroxy-6-((4-(2-(2- hydroxyethyl)nicotinoyl)- thiomorpholin-3-yl)-methoxy)benzaldehyde 11

(S)-2-hydroxy-6-((1-(2- (hydroxymethyl)nicotinoyl)-piperidin-2-yl)methoxy)- benzaldehyde 12

(S)-2-hydroxy-6-((4-(2- (hydroxymethyl)nicotinoyl)-morpholin-3-yl)methoxy)- benzaldehyde 13 (Enantiomer 1)

2-hydroxy-6-((4-(2- (hydroxymethyl)nicotinoyl)- thiomorpholin-3-yl)-methoxy)benzaldehyde 13 (Enantiomer 2)

2-hydroxy-6-((4-(2- (hydroxymethyl)nicotinoyl)- thiomorpholin-3-yl)-methoxy)benzaldehyde 14

(S)-2-hydroxy-6-((1-(2-(2- methoxyethyl)benzoyl)-piperidin-2-yl)methoxy)- benzaldehyde 15

(S)-3-(2-(2-((2-formyl-3- hydroxyphenoxy)methyl)-piperidine-1-carbonyl)- phenyl)propanenitrile 16

(S)-2-hydroxy-6-((1-(3-(2- hydroxyethyl)picolinoyl)-piperidin-2-yl)methoxy)- benzaldehyde 17

(S)-2-hydroxy-6-((1-(2-(2- (pyrrolidin-1-yl)ethyl)-benzoyl)piperidin-2-yl)- methoxy)benzaldehyde 18

(S)-2-hydroxy-6-((1-(2-(3- hydroxypropyl)nicotinoyl)-piperidin-2-yl)methoxy)- benzaldehyde 19

(S)-2-hydroxy-6-((1-(3-(2- hydroxyethyl)pyrazine-2-carbonyl)pyrrolidin-2-yl)- methoxy)benzaldehyde 20

(S)-2-hydroxy-6-((4-(2-(2- methoxyethyl)nicotinoyl)-morpholin-3-yl)methoxy)- benzaldehyde 21

(S)-2-hydroxy-6-((4-(3-(2- hydroxyethyl)pyrazine-2-carbonyl)morpholin-3- yl)methoxy)benzaldehyde 22

(S)-2-hydroxy-6-((4-(2-(2- hydroxyethyl)benzoyl)-morpholin-3-yl)methoxy)- benzaldehyde 23

(S)-2-hydroxy-6-((4-(2- (hydroxymethyl)benzoyl)-morpholin-3-yl)methoxy)- benzaldehyde 24

(S)-2-hydroxy-6-((1-(2-(2- methoxyethyl)nicotinoyl)-pyrrolidin-2-yl)methoxy)- benzaldehyde 25

(S)-2-hydroxy-6-((1-(3-(2- methoxyethyl)pyrazine-2-carbonyl)pyrrolidin-2-yl)- methoxy)benzaldehyde 26

(S)-2-hydroxy-6-((1-(2- (hydroxymethyl)benzoyl)-pyrrolidin-2-yl)methoxy)- benzaldehyde 27

(S)-2-hydroxy-6-((4-(3-(2- methoxyethyl)pyrazine-2-carbonyl)morpholin-3-yl)- methoxy)benzaldehyde 28

(S)-3-(3-(3-((2-formyl-3- hydroxyphenoxy)methyl)-morpholine-4-carbonyl)- pyridin-2-yl)propanenitrile 29

(S)-2-hydroxy-6-((4-(2- (2-methoxyethyl)benzoyl)-morpholin-3-yl)methoxy)- benzaldehyde 30

(S)-3-(3-(2-((2-formyl-3- hydroxyphenoxy)methyl)-pyrrolidine-1-carbonyl)- pyridin-2-yl)propanenitrile 31

(S)-3-(2-(3-((2-formyl-3- hydroxyphenoxy)methyl)-morpholine-4-carbonyl)- (phenyl)propanenitrile 32

(S)-3-(3-(3-((2-formyl-3- hydroxyphenoxy)methyl)-morpholine-4-carbonyl)- pyrazin-2-yl)propanenitrile 33

(S)-2-hydroxy-6-((4-(3- (hydroxymethyl)pyrazine- 2-carbonyl)morpholin-3-yl)methoxy)benzaldehyde 34

2-(((2S)-1-(2-(1,2- dihydroxyethyl)benzoyl)- piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde 34 (Diastereomer 1)

2-(((2S)-1-(2-(1,2- dihydroxyethyl)benzoyl)- piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde 34 (Diastereomer 2)

2-(((2S)-1-(2-(1,2- dihydroxyethyl)benzoyl)- piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde 35 (Diastereomer 1)

2-(((3R)-4-(2-(1,2- dihydroxyethyl)benzoyl)- thiomorpholin-3-yl)-methoxy)-6-hydroxy- benzaldehyde 35 (Diastereomer 2)

2-(((3R)-4-(2-(1,2- dihydroxyethyl)benzoyl)- thiomorpholin-3-yl)-methoxy)-6-hydroxy- benzaldehyde 36

2-{[(2S)-1-[2-(1,2- dihydroxyethyl)pyridine- 3-carbonyl]piperidin-2-yl]methoxy}-6-hydroxy- benzaldehyde 37

(R)-2-hydroxy-6-((4-(2- (2-hydroxyethyl)- nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde 38

(R)-2-hydroxy-6-((1-(2- (2-hydroxyethyl)- nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde 39

(S)-2-hydroxy-6-((4-(2-(2- hydroxy-2-methylpropyl)-nicotinoyl)morpholin-3- yl)methoxy)benzaldehyde 40

2-hydroxy-6-((4-(2- (hydroxymethyl)benzoyl)- thiomorpholin-3-yl)-methoxy)benzaldehyde 40 (Enantiomer 1)

2-hydroxy-6-((4-(2- (hydroxymethyl)benzoyl)- thiomorpholin-3-yl)-methoxy)benzaldehyde 40 (Enantiomer 2)

2-hydroxy-6-((4-(2- (hydroxymethyl)benzoyl)-thiomorpholin-3-yl)-methoxy)benzaldehyde 41 (Diastereomer 1)

2-hydroxy-6-(((3S)-4- (2-(1-hydroxyethyl)- nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde 41 (Diastereomer 2)

2-hydroxy-6-(((3S)-4- (2-(1-hydroxyethyl)- nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde 42 (Diastereomer 1)

2-hydroxy-6-(((3S)-4- (2-(2-hydroxypropyl)- nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde 42 (Diastereomer 2)

2-hydroxy-6-(((3S)-4- (2-(2-hydroxypropyl)- nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde 43 (Diastereomer 1)

2-hydroxy-6-(((3R)-4-(2-(1- hydroxyethyl)nicotinoyl)-thiomorpholin-3-yl)- methoxy)benzaldehyde 43 (Diastereomer 2)

2-hydroxy-6-(((3R)-4-(2- (1-hydroxyethyl)nicotin-oyl)thiomorpholin-3-yl)- methoxy)benzaldehyde 44 (Diastereomer 1)

2-hydroxy-6-(((3R)-4-(2- (2-hydroxypropyl)nicotin-oyl)thiomorpholin-3-yl)- methoxy)benzaldehyde 44 (Diastereomer 2)

2-hydroxy-6-(((3R)-4-(2- (2-hydroxypropyl)nicotin-oyl)thiomorpholin-3-yl)- methoxy)benzaldehyde

TABLE 2 Structure

Provided herein is a compound selected from Table 6, or an isotopicallyenriched analog, stereoisomer, mixture of stereoisomers, or prodrugthereof, or a pharmaceutically acceptable salt of each thereof, andexcluding Reference Compound A, B, and C. Provided herein is a compoundselected from Table 6, or a pharmaceutically acceptable salt thereof,and excluding Reference Compound A, B, and C. Provided herein is acompound selected from Table 6 and excluding Reference Compound A, B,and C.

Provided herein is a compound selected from Table 7, or an isotopicallyenriched analog, stereoisomer, mixture of stereoisomers, or prodrugthereof, or a pharmaceutically acceptable salt of each thereof, andexcluding Reference Compound A and B. Provided herein is a compoundselected from Table 7, or a pharmaceutically acceptable salt thereof,and excluding Reference Compound A and B. Provided herein is a compoundselected from Table 7 and excluding Reference Compound A and B.

Treatment Methods and Uses

“Treatment” or “treating” is an approach for obtaining beneficial ordesired results including clinical results. Beneficial or desiredclinical results may include one or more of the following: a) inhibitingthe disease or condition (e.g., decreasing one or more symptomsresulting from the disease or condition, and/or diminishing the extentof the disease or condition); b) slowing or arresting the development ofone or more clinical symptoms associated with the disease or condition(e.g., stabilizing the disease or condition, preventing or delaying theworsening or progression of the disease or condition, and/or preventingor delaying the spread (e.g., metastasis) of the disease or condition);and/or c) relieving the disease, that is, causing the regression ofclinical symptoms (e.g., ameliorating the disease state, providingpartial or total remission of the disease or condition, enhancing effectof another medication, delaying the progression of the disease,increasing the quality of life, and/or prolonging survival.

“Prevention” or “preventing” means any treatment of a disease orcondition that causes the clinical symptoms of the disease or conditionnot to develop. Compounds may, in some embodiments, be administered to asubject (including a human) who is at risk or has a family history ofthe disease or condition.

“Subject” refers to an animal, such as a mammal (including a human),that has been or will be the object of treatment, observation orexperiment. The methods described herein may be useful in human therapyand/or veterinary applications. In some embodiments, the subject is amammal. In one embodiment, the subject is a human

The term “therapeutically effective amount” or “effective amount” of acompound described herein or a pharmaceutically acceptable salt,tautomer, stereoisomer, mixture of stereoisomers, prodrug, or deuteratedanalog thereof means an amount sufficient to effect treatment whenadministered to a subject, to provide a therapeutic benefit such asamelioration of symptoms or slowing of disease progression. For example,a therapeutically effective amount may be an amount sufficient todecrease a symptom of a sickle cell disease. The therapeuticallyeffective amount may vary depending on the subject, and disease orcondition being treated, the weight and age of the subject, the severityof the disease or condition, and the manner of administering, which canreadily be determined by one of ordinary skill in the art.

The methods described herein may be applied to cell populations in vivoor ex vivo. “In vivo” means within a living individual, as within ananimal or human In this context, the methods described herein may beused therapeutically in an individual. “Ex vivo” means outside of aliving individual. Examples of ex vivo cell populations include in vitrocell cultures and biological samples including fluid or tissue samplesobtained from individuals. Such samples may be obtained by methods wellknown in the art. Exemplary biological fluid samples include blood,cerebrospinal fluid, urine, and saliva. In this context, the compoundsand compositions described herein may be used for a variety of purposes,including therapeutic and experimental purposes. For example, thecompounds and compositions described herein may be used ex vivo todetermine the optimal schedule and/or dosing of administration of acompound of the present disclosure for a given indication, cell type,individual, and other parameters. Information gleaned from such use maybe used for experimental purposes or in the clinic to set protocols forin vivo treatment. Other ex vivo uses for which the compounds andcompositions described herein may be suited are described below or willbecome apparent to those skilled in the art. The selected compounds maybe further characterized to examine the safety or tolerance dosage inhuman or non-human subjects. Such properties may be examined usingcommonly known methods to those skilled in the art.

The term “hemoglobin” as used herein refers to any hemoglobin protein,including normal hemoglobin (HbA) and abnormal hemoglobin, such assickle hemoglobin (HbS).

The term “sickle cell disease” refers to diseases mediated by sicklehemoglobin (HbS) that results from a single point mutation in thehemoglobin (Hb). Sickle cell diseases include sickle cell anemia (HbSS),hemoglobin SC disease (HbSC), hemoglobin S beta-plus-thalassemia(HbS/β+) and hemoglobin S beta-zero-thalassemia (HbS/β0).

Provided herein are methods for treating sickle cell disease (SCD).Sickle hemoglobin (HbS) contains a point mutation where glutamic acid isreplaced with valine, making HbS susceptible to polymerization underhypoxic conditions to give the HbS containing red blood cells theircharacteristic sickle shape. The sickled cells are also more rigid thannormal red blood cells, and their lack of flexibility can lead toblockage of blood vessels. It is contemplated that an approach totherapy would be to maintain the HbS in the oxygenated state, aspolymerization occurs only in the deoxygenated state under hypoxicconditions.

In some embodiments, provided herein is a method for increasing oxygenaffinity of hemoglobin S in a subject in need thereof, comprisingadministering to the subject a compound as described herein or anisotopically enriched analog, stereoisomer, mixture of stereoisomers, orprodrug thereof, or a pharmaceutically acceptable salt of each thereof,or a pharmaceutical composition as described herein. In someembodiments, provided herein is a method for increasing oxygen affinityof hemoglobin S in a subject in need thereof, comprising administeringto the subject a compound as described herein or a pharmaceuticalcomposition as described herein.

In some embodiments, provided herein is a method for treating a disordermediated by hemoglobin in a subject in need thereof, comprisingadministering to the subject a compound as described herein or anisotopically enriched analog, stereoisomer, mixture of stereoisomers, orprodrug thereof, or a pharmaceutically acceptable salt of each thereof,or a pharmaceutical composition as described herein. In someembodiments, provided herein is a method for treating a disordermediated by hemoglobin in a subject in need thereof, comprisingadministering to the subject a compound as described herein or apharmaceutical composition as described herein. In some embodiments, thedisorder is a hemoglobinopathy.

In some embodiments, the hemoglobin is sickle hemoglobin.

In some embodiments, provided herein is a method for treating sicklecell disease in a subject in need thereof, comprising administering tothe subject a compound as described herein or an isotopically enrichedanalog, stereoisomer, mixture of stereoisomers, or prodrug thereof, or apharmaceutically acceptable salt of each thereof, or a pharmaceuticalcomposition as described herein. In some embodiments, provided herein isa method for treating sickle cell disease in a subject in need thereof,comprising administering to the subject a compound as described hereinor a pharmaceutical composition as described herein.

Pharmaceutical Compositions and Modes of Administration

Compounds provided herein are usually administered in the form ofpharmaceutical compositions. Thus, provided herein are alsopharmaceutical compositions that comprise one or more of the compoundsdescribed herein or an isotopically enriched analog, stereoisomer,mixture of stereoisomers, or prodrug thereof, or a pharmaceuticallyacceptable salt of each thereof and one or more pharmaceuticallyacceptable vehicles selected from carriers, adjuvants and excipients.Suitable pharmaceutically acceptable vehicles may include, for example,inert solid diluents and fillers, diluents, including sterile aqueoussolution and various organic solvents, permeation enhancers,solubilizers and adjuvants. Such compositions are prepared in a mannerwell known in the pharmaceutical art. See, e.g., Remington'sPharmaceutical Sciences, Mace Publishing Co., Philadelphia, Pa. 17th Ed.(1985); and Modern Pharmaceutics, Marcel Dekker, Inc. 3rd Ed. (G.S.Banker & C.T. Rhodes, Eds.).

The pharmaceutical compositions may be administered in either single ormultiple doses. The pharmaceutical composition may be administered byvarious methods including, for example, rectal, buccal, intranasal andtransdermal routes. In certain embodiments, the pharmaceuticalcomposition may be administered by intra-arterial injection,intravenously, intraperitoneally, parenterally, intramuscularly,subcutaneously, orally, topically, or as an inhalant.

One mode for administration is parenteral, for example, by injection.The forms in which the pharmaceutical compositions described herein maybe incorporated for administration by injection include, for example,aqueous or oil suspensions, or emulsions, with sesame oil, corn oil,cottonseed oil, or peanut oil, as well as elixirs, mannitol, dextrose,or a sterile aqueous solution, and similar pharmaceutical vehicles.

Oral administration may be another route for administration of thecompounds described herein. Administration may be via, for example,capsule or enteric coated tablets. In making the pharmaceuticalcompositions that include at least one compound described herein or anisotopically enriched analog, stereoisomer, mixture of stereoisomers, orprodrug thereof, or a pharmaceutically acceptable salt of each thereof,the active ingredient is usually diluted by an excipient and/or enclosedwithin such a carrier that can be in the form of a capsule, sachet,paper or other container. When the excipient serves as a diluent, it canbe in the form of a solid, semi-solid, or liquid material, which acts asa vehicle, carrier or medium for the active ingredient. Thus, thecompositions can be in the form of tablets, pills, powders, lozenges,sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups,aerosols (as a solid or in a liquid medium), ointments containing, forexample, up to 10% by weight of the active compound, soft and hardgelatin capsules, sterile injectable solutions, and sterile packagedpowders.

Some examples of suitable excipients include lactose, dextrose, sucrose,sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates,tragacanth, gelatin, calcium silicate, microcrystalline cellulose,polyvinylpyrrolidone, cellulose, sterile water, syrup, and methylcellulose. The formulations can additionally include lubricating agentssuch as talc, magnesium stearate, and mineral oil; wetting agents;emulsifying and suspending agents; preserving agents such as methyl andpropylhydroxy-benzoates; sweetening agents; and flavoring agents.

The compositions that include at least one compound described herein oran isotopically enriched analog, stereoisomer, mixture of stereoisomers,or prodrug thereof, or a pharmaceutically acceptable salt of eachthereof can be formulated so as to provide quick, sustained or delayedrelease of the active ingredient after administration to the subject byemploying procedures known in the art. Controlled release drug deliverysystems for oral administration include osmotic pump systems anddissolutional systems containing polymer-coated reservoirs ordrug-polymer matrix formulations. Examples of controlled release systemsare given in U.S. Pat. Nos. 3,845,770; 4,326,525; 4,902,514; and5,616,345. Another formulation for use in the methods disclosed hereinemploy transdermal delivery devices (“patches”). Such transdermalpatches may be used to provide continuous or discontinuous infusion ofthe compounds described herein in controlled amounts. The constructionand use of transdermal patches for the delivery of pharmaceutical agentsis well known in the art. See, e.g., U.S. Pat. Nos. 5,023,252, 4,992,445and 5,001,139. Such patches may be constructed for continuous,pulsatile, or on demand delivery of pharmaceutical agents.

For preparing solid compositions such as tablets, the principal activeingredient may be mixed with a pharmaceutical excipient to form a solidpreformulation composition containing a homogeneous mixture of acompound described herein or an isotopically enriched analog,stereoisomer, mixture of stereoisomers, or prodrug thereof, or apharmaceutically acceptable salt of each thereof. When referring tothese preformulation compositions as homogeneous, the active ingredientmay be dispersed evenly throughout the composition so that thecomposition may be readily subdivided into equally effective unit dosageforms such as tablets, pills and capsules.

The tablets or pills of the compounds described herein may be coated orotherwise compounded to provide a dosage form affording the advantage ofprolonged action, or to protect from the acid conditions of the stomach.For example, the tablet or pill can include an inner dosage and an outerdosage component, the latter being in the form of an envelope over theformer. The two components can be separated by an enteric layer thatserves to resist disintegration in the stomach and permit the innercomponent to pass intact into the duodenum or to be delayed in release.A variety of materials can be used for such enteric layers or coatings,such materials including a number of polymeric acids and mixtures ofpolymeric acids with such materials as shellac, cetyl alcohol, andcellulose acetate.

Compositions for inhalation or insufflation may include solutions andsuspensions in pharmaceutically acceptable, aqueous or organic solvents,or mixtures thereof, and powders. The liquid or solid compositions maycontain suitable pharmaceutically acceptable excipients as describedherein. In some embodiments, the compositions are administered by theoral or nasal respiratory route for local or systemic effect. In otherembodiments, compositions in pharmaceutically acceptable solvents may benebulized by use of inert gases. Nebulized solutions may be inhaleddirectly from the nebulizing device or the nebulizing device may beattached to a facemask tent, or intermittent positive pressure breathingmachine. Solution, suspension, or powder compositions may beadministered, preferably orally or nasally, from devices that deliverthe formulation in an appropriate manner

Dosing

The specific dose level of a compound of the present application for anyparticular subject will depend upon a variety of factors including theactivity of the specific compound employed, the age, body weight,general health, sex, diet, time of administration, route ofadministration, and rate of excretion, drug combination and the severityof the particular disease in the subject undergoing therapy. Forexample, a dosage may be expressed as a number of milligrams of acompound described herein per kilogram of the subject's body weight(mg/kg). Dosages of between about 0.1 and 150 mg/kg may be appropriate.In some embodiments, about 0.1 and 100 mg/kg may be appropriate. Inother embodiments a dosage of between 0.5 and 60 mg/kg may beappropriate. Normalizing according to the subject's body weight isparticularly useful when adjusting dosages between subjects of widelydisparate size, such as occurs when using the drug in both children andadult humans or when converting an effective dosage in a non-humansubject such as dog to a dosage suitable for a human subject.

Synthesis of the Compounds

The compounds may be prepared using the methods disclosed herein androutine modifications thereof, which will be apparent given thedisclosure herein and methods well known in the art. Conventional andwell-known synthetic methods may be used in addition to the teachingsherein. The synthesis of typical compounds described herein may beaccomplished as described in the following examples. If available,reagents may be purchased commercially, e.g., from Sigma Aldrich orother chemical suppliers.

General Synthesis

Typical embodiments of compounds described herein may be synthesizedusing the general reaction schemes described below. It will be apparentgiven the description herein that the general schemes may be altered bysubstitution of the starting materials with other materials havingsimilar structures to result in products that are correspondinglydifferent. Descriptions of syntheses follow to provide numerous examplesof how the starting materials may vary to provide correspondingproducts. Given a desired product for which the substituent groups aredefined, the necessary starting materials generally may be determined byinspection. Starting materials are typically obtained from commercialsources or synthesized using published methods. For synthesizingcompounds which are embodiments described in the present disclosure,inspection of the structure of the compound to be synthesized willprovide the identity of each substituent group. The identity of thefinal product will generally render apparent the identity of thenecessary starting materials by a simple process of inspection, giventhe examples herein. In general, compounds described herein aretypically stable and isolatable at room temperature and pressure.

In some embodiments, a compound of formula I can be synthesized byexemplary synthetic pathways as shown in Schemes A and B.

In some embodiments of Scheme A, R² can be hydroxyl or chloro; R¹ can bemono-hydroxy-(C₁₋₄ alkyl), CH₂CH₂OCH₃, —CH₂CH₂CN,

or 1 and X, Y, and Z are as described herein. As shown in Scheme A,compound A1 and compound A2 are coupled first utilizing standardcoupling conditions to give compound A3, which can be then assembledonto 2,6-dihydroxybenzaldehyde A4 to produce compound of formula I. Insome embodiments, when R¹ is mono-hydroxy-(C₁₋₄ alkyl) of a compound offormula I, the hydroxy group of the R¹ moiety of Al includes a hydroxyprotecting group known in the art; the protecting group may besubsequently removed after coupling A3 to A4 utilizing standardprocedures, thereby producing a compound of formula I.

In some embodiments of Scheme B, R³ can be a C₂₋₄alkene; R² can behydroxyl or chloro; R¹ can be di-hydroxy-(C₂₋₄ alkyl); Q is a halo; PGis a hydroxy protecting group; and X, Y, and Z are as described herein.As shown in Scheme B, compound B1 and compound B2 are coupled firstutilizing standard coupling conditions to give compound B3. Standarddeprotection procedures provides compound B4, which can be thenassembled onto 2,6-dihydroxybenzaldehyde A4 to produce compound B5.Introduction of the alkene (e.g. via Stille coupling) provides compoundB6, which can then be converted to a compound of formula I viadihydroxylation procedures known in the art.

EXAMPLES

The following examples are included to demonstrate specific embodimentsof the disclosure. It should be appreciated by those of skill in the artthat the techniques disclosed in the examples which follow representtechniques to function well in the practice of the disclosure, and thuscan be considered to constitute specific modes for its practice.However, those of skill in the art should, in light of the presentdisclosure, appreciate that many changes can be made in the specificembodiments which are disclosed and still obtain a like or similarresult without departing from the spirit and scope of the disclosure.

SYNTHETIC EXAMPLES Example 1. Synthesis of(S)-2-hydroxy-6-((1-(2-(2-hydroxyethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde,Compound 1

Compound 1 was synthesized according to Scheme 1A.

Step 1: Synthesis of 2-(3-bromopyridin-2-yl)ethan-1-ol (1b)

Into a 100-mL 3-necked round-bottom flask, was placed a solution ofethyl 2-(3-bromopyridin-2-yl)acetate (la) (4 g, 16.39 mmol, 1 equiv) intetrahydrofuran (“THF”) (40 mL). This was followed by the addition ofdiisobutylaluminum hydride (“DIBAL-H”) in THF (16 mL, 32.00 mmol, 1.95equiv) dropwise with stirring at −78° C. The resulting mixture wasallowed to warm to rt and was stirred for additional 3 hr at 25° C. Thereaction was then quenched by the addition of 50 mL of saturated NH₄Cl.The resulting solution was extracted with 3×100 mL of ethyl acetate andthe organic layers combined, washed with 2×100 mL of brine The separatedorganic layer was dried over Na₂SO₄, active carbon, filtered and thenconcentrated. The residue was applied onto a silica gel column andeluted with ethyl acetate/petroleum ether (1:3) to provide the titlecompound. LCMS (ES) [M+1]⁺ m/z 202.0.

Step 2: Synthesis of3-bromo-2-(2-((tert-butyldimethylsilyl)oxy)ethyl)pyridine (1c)

Into a 100-mL round-bottom flask, was placed a solution of2-(3-bromopyridin-2-yl)ethan-1-ol (1.9 g, 9.40 mmol, 1 equiv) indimethylformamide (“DMF”) (20 mL), 1H-imidazole (1.3 g, 18.81 mmol, 2equiv), 4-dimethylaminopyridine (“DMAP”) (0.1 g, 0.94 mmol, 0.1 equiv),tert-butyl(chloro)dimethylsilane (2.8 g, 18.81 mmol, 2 equiv). Theresulting solution was heated to 50° C. and stirred for 2 hr. Thereaction mixture was cooled and extracted with 2×50 mL of ethyl acetate.The combined organic layers was washed with 2×50 mL of brine, dried overNa₂SO₄, filtered and concentrated. The residue was applied onto a silicagel column and eluted with ethyl acetate/petroleum ether (1:3) toprovide the title compound. LCMS (ES) [M+1]⁺ m/z 316.1.

Alternatively, a tert-butyldiphenylsilyl (TBDPS) protecting group can beused instead of tert-butyl(chloro)dimethylsilyl (TBS). In typicalconditions, imidazole (1.5 to 4 eq) and tert-butyl(chloro)diphenylsilane(TBDPSC1 (about 1 eq.) were added to a solution of alcohol 1b (1 eq) inDCM (3 to 15 V). The reaction mixture was stirred at RT for 1 to 48hours. This gave the product (1c2) after normal workup and purification.The TBDPS group can be removed using TBAF (1-3 eq) following typicalliterature conditions. Compounds 8 and 12 can be synthesized using TBDPSas a protecting group.

Step 3: Synthesis of methyl2-(2-((tert-butyldimethylsilyl)oxy)ethyl)nicotinate (1d)

Into a 250-mL sealed tube, was placed a solution of3-bromo-2-[2-[(tert-butyldimethylsilyl)oxy] ethyl]pyridine (2.0 g, 6.32mmol, 1 equiv) in methanol (“MeOH,” 100 mL), triethylamine (“TEA,” 1.3g, 12.65 mmol, 2 equiv), and[1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II)(“Pd(dppf)Cl₂,” 0.5 g, 0.63 mmol, 0.1 equiv). The resulting solution wasstirred for 16 hr at 100° C. under CO atmosphere (10 atm). After coolingto rt, the reaction mixture was filtered and the filtrate wasconcentrated. The resulting residue was applied onto a silica gel columnand eluted with ethyl acetate/petroleum ether (1:3) to provide the titlecompound. LCMS (ES) [M+1]⁺ m/z 296.2.

Alternative Synthesis: Scheme 1B

Alternatively, phenyl formate can be used to replace CO gas as acarbonyl source, in the presence of triethylamine (2 eq), catalyticamounts of palladium acetate (e.g., 0.02 eq) andtri-tert-butylphosphonium tetrafluoroborate (e.g., 0.08 eq), to convertthe bromide 1c2 into carboxylate 1d2 in acetonitrile (3 to 10 V) underheating (80° C.) for 2 to 48 hours, and then directly to carboxylic acidle2 by hydrolysis of the ester under basic aqueous conditions (K₂CO₃ 2-8eq in 3 to 10 V water; 50 to 80° C. for up to 48 hours).

Step 4: Synthesis of 2-(2-((tert-butyldimethylsilyl)oxy)ethyl)nicotinicacid (1e)

Into a 100-mL round-bottom flask, was placed a solution of methyl2-[2-[(tert-butyldimethylsilyl) oxy]ethyl]pyridine-3-carboxylate (1.7 g,5.75 mmol, 1 equiv) in MeOH (20 mL), and a solution of LiOH (275.6 mg,11.51 mmol, 2 equiv) in H₂O (5 mL). The resulting solution was stirredfor 4 hr at 25° C. Water (10 ml) was added to the reaction mixture,crude product as precipitate was collected by filtration. The crudeproduct was then purified by Flash-Prep-HPLC using the followingconditions (IntelFlash-1): Column, C18 silica gel; mobile phase,H₂O:acetonitrile (“ACN”)=10:1 increasing to H₂O:ACN=3:1 within 10 min toprovide the title compound. LCMS (ES) [M+1]⁺ m/z 282.1.

Step 5. Synthesis of(S)-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)pyridin-3-yl)(2-(hydroxymethyl)piperidin-1-yl)methanone(1f)

Into a 100-mL round-bottom flask, was placed2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carboxylic acid (1.4g, 4.97 mmol, 1 equiv), [(2S)-piperidin-2-yl]methanol (0.9 g, 7.46 mmol,1.5 equiv), N,N-diisopropylethylamine (“DIEA,” 1.3 g, 9.95 mmol, 2equiv),1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium3-oxid hexafluorophosphate (“HATU,” 2.8 g, 7.46 mmol, 1.5 equiv) and 30mL of dichloromethane (“DCM”). The resulting reaction mixture wasstirred for 2 hr at 25° C. and then diluted with 60 mL of H₂O. Theorganic phase was extracted with 3×50 mL of ethyl acetate. The combinedorganic layers was dried over Na₂SO₄, filtered and concentrated. Theresidue was applied onto a silica gel column and eluted with ethylacetate/petroleum ether (1:3) to provide the title compound. LCMS (ES)[M+1]⁺ m/z 379.2.

Steps 6 & 7: Synthesis of(S)-2-hydroxy-6-((1-(2-(2-hydroxyethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde(Compound 1)

Into a 100-mL round-bottom flask, was placed a solution of[(2S)-1-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)piperidin-2-yl]methanol(900 mg, 2.38 mmol, 1 equiv) in DCM (8 mL), 2,6-dihydroxybenzaldehyde(656.7 mg, 4.75 mmol, 2 equiv), and triphenylphosphine (“PPh₃,” 1247.0mg, 4.75 mmol, 2 equiv). This was followed by the addition of a solutionof di-tert-butyl azodicarboxylate (“DBAD,” 1094.8 mg, 4.75 mmol, 2equiv) in DCM (2 mL) dropwise with stirring at 0° C. The resultingsolution was stirred for 2 hr at 25° C. The reaction mixture wasconcentrated and dissolved in 20 mL THF. To this was addedtetrabutylammonium fluoride (“TBAF,” 1243.1 mg, 4.75 mmol, 2 equiv). Theresulting mixture was allowed to stir for 2 hr at 25° C. The reactionmixture was concentrated to give a crude product, which was purified byPrep-HPLC with the following conditions (Prep-HPLC-006): Column, XBridgePrep C18 OBD Column, 19 mm×150 mm 5 um; mobile phase, Water(10 mmoL/LNH₄HCO₃+0.1% NH₃.H₂O) and ACN (14% Phase B up to 35% in 8 min, hold 95%in 1 min, down to 14% in 1 min, hold 14% in 1 min); Detector, UV 254 nm.This provided the title compound. ¹HTEM NMR (300 MHz, 353K,dimethylsulfoxide (“DMSO”)-d₆): δ 11.36 (s, 1H), 10.25 (s, 1H), 8.51(dd, J=4.8, 1.8 Hz, 1H), 7.51-723 (m, 3H), 6.7-6.5 (m, 2H), 5.15 (s,1H), 4.59-3.98 (m, 3H), 3.78 (br, 2H), 3.17-2.86 (m, 4H), 1.83-1.37 (m,6H). LCMS (ES) [M+1]⁺ m/z 385.2.

Example 2:(S)-2-hydroxy-6-((1-(2-(2-methoxyethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde,Compound 2

Compound 2 was synthesized according to Scheme 2.

Step 1: Synthesis of methyl 2-ethenylpyridine-3-carboxylate (2b)

Into a 100-mL round-bottom flask, was placed a mixture of methyl2-chloropyridine-3-carboxylate (3 g, 17.48 mmol, 1.00 equiv), dioxane(40 mL), water (4 mL), 2-ethenyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(5.39 g, 34.99 mmol, 2.00 equiv), Cs₂CO₃ (11.40 g, 34.99 mmol, 2.00equiv) and tetrakis(triphenylphosphine)palladium(0) (“Pd(PPh₃)₄,” 2.02g, 1.75 mmol, 0.10 equiv). The resulting solution was stirred for 2 h at100° C. under N₂. The reaction mixture was cooled, filtered, andconcentrated under vacuum. The resulting residue was purified by asilica gel column by eluting with ethyl acetate/petroleum ether (1/2) togive 2 methyl 2-ethenylpyridine-3-carboxylate. LCMS (ES) [M+1]⁺ m/z:164.1.

Step 2: Synthesis of methyl 2-(2-methoxyethyl)pyridine-3-carboxylate(2c)

Into a 100-mL round-bottom flask, was placed a solution of methyl2-ethenylpyridine-3-carboxylate (1.5 g, 9.19 mmol, 1.00 equiv), methanol(20 mL) and aqueous hydrogen chloride (36%, 2 mL). The resultingsolution was stirred for 48 h at 60° C. The mixture was cooled and thenconcentrated under vacuum to give methyl2-(2-methoxyethyl)pyridine-3-carboxylate). LCMS (ES) [M+1]⁺ m/z: 196.1.

Step 3: Synthesis of 2-(2-methoxyethyl)pyridine-3-carboxylic acid (2d)

Into a 100-mL round-bottom flask, was placed a solution of methyl2-(2-methoxyethyl)pyridine-3-carboxylate (2.50 g, 12.81 mmol, 1.00equiv), methanol (30 mL), H₂O (6 mL) and NaOH (2.56 g, 64.00 mmol, 5.00equiv). The resulting solution was stirred for 2 h at 50° C. Thereaction was cooled, pH adjusted to 6 with addition of aqueous hydrogenchloride (2 M). The mixture was extracted with 3×50 mL of DCM/MeOH(10/1). The combined organic layers was washed with 1×100 mL of brine,dried over anhydrous sodium sulfate and concentrated under vacuum toproduce (crude) 2-(2-methoxyethyl)pyridine-3-carboxylic acid. LCMS (ES)[M+1]⁺ m/z: 182.1.

Step 4: Synthesis of[(2S)-1-[[2-(2-methoxyethyl)pyridin-3-yl]carbonyl]piperidin-2-yl]methanol(2e)

Into a 100-mL round-bottom flask, was placed a solution of2-(2-methoxyethyl)pyridine-3-carboxylic acid (600 mg, 3.31 mmol, 1.00equiv), dichloromethane (30 mL), (2S)-piperidin-2-ylmethanol (762 mg,6.62 mmol, 2.00 equiv), DIEA (855 mg, 6.62 mmol, 2.00 equiv) and HATU(1.89 g, 4.97 mmol, 1.50 equiv). The resulting solution was stirred for1 h at rt. The crude reaction mixture was filtered and concentrated. Theresulting residue was purified by reverse preparative HPLC (Prep-C18,20-45 μM, 120 g, Tianjin Bonna-Agela Technologies; gradient elution of15% CH₃CN in water to 40% CH₃CN in water over a 12 min period, whereboth solvents contain 0.1% ammonia) to provide[(2S)-1-[[2-(2-methoxyethyl)pyridin-3-yl]carbonyl]piperidin-2-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 279.1.

Step 5:(S)-2-hydroxy-6-((1-(2-(2-methoxyethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde(Compound 2)

Into a 50-mL 3-necked round-bottom flask, was placed a solution of[(2S)-1-[[2-(2-methoxyethyl)pyridin-3-yl]carbonyl]piperidin-2-yl]methanol(265 mg, 0.95 mmol, 1.00 equiv), dichloromethane (10 mL),2,6-dihydroxybenzaldehyde (263 mg, 1.90 mmol, 2.00 equiv) and PPh₃ (499mg, 1.90 mmol, 2.00 equiv). It was added the solution of dibenzylazodicarboxylate (“DBAD”) (438 mg, 1.90 mmol, 2.00 equiv) in DCM (5 mL)under N₂ at 0° C. The resulting solution was stirred for 2 h at roomtemperature. The resulting mixture was concentrated under vacuum. Theresidue was purified by a silica gel column eluted with ethylacetate/petroleum ether (1/1). The crude reaction mixture was filteredand subjected to reverse preparative HPLC (Prep-C18, 5 mM XBridgecolumn, 19×150 mm, waters; gradient elution of 22% CH₃CN in water to 42%CH₃CN in water over a 6 mM period, where both solvents contain 0.1%trifluoroacetic acid (“TFA”)) to provide2-hydroxy-6-[(1-[hydroxy[2-(2-methoxyethyl)piperidin-3-yl]methyl]piperidin-2-yl]methoxylcyclohexane-1-carbaldehyde.

¹HTEM NMR (300 MHz, 353 K, DMSO-d₆) δ 11.64(s, 1H), 10.28(s, 1H),8.56(dd, J=5.1 Hz, 1.8 Hz, 1H), 7.78-7.59(m, 1H), 7.52(t, J=8.1 Hz, 1H),7.39-7.21(m, 1H), 6.72(s, 1H), 6.55(d, J=8.4 Hz, 1H) , 5.19(s, 1H),4.33-4.21(m, 3H), 3.83-3.57(m, 2H), 3.30-3.08(m, 4H), 3.04-2.84(m,2H),2.01-1.82(m, 1H), 1.82-1.55(m, 4H), 1.55-1.28(m, 1H). LCMS (ES) [M+1]⁺m/z: 399.1.

Example 3:(S)-3-(3-(2-((2-formyl-3-hydroxyphenoxy)methyl)piperidine-1-carbonyl)pyridin-2-yl)propanenitrile,Compound 3

Compound 3 was synthesized according to Scheme 3.

Step 1: Synthesis of methyl 2-formylnicotinate (3b)

Into a 100-mL round-bottom flask, was placed a solution of methyl2-methylpyridine-3-carboxylate (5 g, 33.08 mmol, 1 equiv) in dioxane (50mL), (oxo-lambda4-selanylidene)oxidane (selenium dioxide) (5.5 g, 49.61mmol, 1.5 equiv). After stirring for 16 hr at 110° C. the reactionmixture was cooled to rt, concentrated, and diluted with 100 mL of H₂O.It was then extracted with 4×100 ml of ethyl acetate and the organiclayers combined. The organic layers was washed with 200 ml of brine,dried over Na₂SO₄ and concentrated. The resulting residue was appliedonto a silica gel column and eluted with ethyl acetate/petroleum ether(1:5) to provide the title compound. LCMS (ES) [M+1]⁺ m/z 166.0.

Step 2: Synthesis of methyl (E)-2-(2-cyanovinyl)nicotinate (3c)

Into a 100-mL round-bottom flask, was placed a solution of methyl2-formylpyridine-3-carboxylate (2.5 g, 15.14 mmol, 1 equiv) in THF (30mL). This was followed by the addition of diethyl(cyanomethyl)phosphonate (3.2 g, 18.17 mmol, 1.2 equiv) at 0° C. and(tert-butoxy)potassium (2.5 g, 22.71 mmol, 1.5 equiv), in portions at 0°C. The resulting mixture was stirred for 16 hr at room temperature. Thesolids were filtered out. The filtrate was diluted with 100 mL of H₂Oand extracted with 2×80 mL of ethyl acetate. The combined organic layerswas washed with 2×100 mL of brine, dried over Na₂SO₄, filtered andconcentrated. The resulting residue was applied onto a silica gel columnand eluted with ethyl acetate/petroleum ether (1:5) to provide the titlecompound. LCMS (ES) [M+1]⁺ m/z 189.1.

Step 3: Synthesis of (E)-2-(2-cyanovinyl)nicotinic acid (3d)

Into a 100-mL round-bottom flask, was placed a solution of methyl2-[(1E)-2-cyanoeth-1-en-1-yl]pyridine-3-carboxylate (1.4 g, 7.44 mmol, 1equiv) in MeOH (20 mL), a solution of NaOH (0.6 g, 14.88 mmol, 2 equiv)in H₂O (4 mL). After stirring for 2 hr at room temperature, the reactionwas diluted with 10 mL of H₂O, pH adjusted to 6-7 with HCl (2 mol/L),and then concentrated. The crude product was purified by Flash-Prep-HPLCwith the following conditions (IntelFlash-1): Column, C18 silica gel;mobile phase, H₂O:ACN=10:1 increasing to H₂O:ACN=1:1 with 10 min. Thisprovided the title compound. LCMS (ES) [M+1]⁺ m/z 175.0.

Step 4: Synthesis of 2-(2-cyanoethyl)nicotinic acid (3e)

Into a 100-mL round-bottom flask, was placed a solution of2-[(1E)-2-cyanoeth-1-en-1-yl]pyridine-3-carboxylic acid (600 mg, 3.45mmol, 1 equiv) in MeOH (20 mL), palladium on carbon (“Pd/C,” 120 mg,1.13 mmol, 0.33 equiv). The resulting solution was stirred for 16 hr atroom temperature under H2 atmosphere (20 atm). The solids were filteredout. The filtrate was concentrated to give the crude product. LCMS (ES)[M+1]⁺ m/z 177.1.

Step 5: Synthesis of(S)-3-(3-(2-(hydroxymethyl)piperidine-1-carbonyl)pyridin-2-yl)propanenitrile(3f)

Into a 50-mL round-bottom flask, was placed a solution of2-[(1E)-2-cyanoeth-1-en-1-yl]pyridine-3-carboxylic acid (550 mg, 3.16mmol, 1 equiv) in DMF (6 mL), [(2S)-piperidin-2-yl]methanol (545.6 mg,4.74 mmol, 1.5 equiv), DIEA (816.3 mg, 6.32 mmol, 2 equiv), HATU (1801.2mg, 4.74 mmol, 1.5 equiv). The resulting solution was stirred for 4 hrat room temperature. The mxiture was diluted with 40 mL of H₂O andextracted with 3×30 mL of ethyl acetate. The combined organic layers waswashed with 30×30 mL of brine, dried over Na₂SO₄, filtered andconcentrated. The resulting residue was purified by Flash-Prep-HPLC withthe following conditions (IntelFlash-1): Column, C18 silica gel; mobilephase, H₂O:ACN=10:1 increasing to H₂O:ACN=1:1 with 10 min This providedthe title compound. LCMS (ES) [M+1]⁺ m/z 274.1.

Step 6: Synthesis of(S)-3-(3-(2-((2-formyl-3-hydroxyphenoxy)methyl)piperidine-1-carbonyl)pyridin-2-yl)propanenitrile(Compound 3)

Into a 50-mL round-bottom flask, was placed a solution of3-[3-[(2S)-2-(hydroxymethyl)piperidine-1-carbonyl]pyridin-2-yl]propanenitrile(200 mg, 0.73 mmol, 1 equiv) in DCM (3 mL), 2,6-dihydroxybenzaldehyde(202.1 mg, 1.46 mmol, 2 equiv), PPh₃ (383.8 mg, 1.46 mmol, 2 equiv).This was followed by the addition of DBAD (337.0 mg, 1.46 mmol, 2 equiv)at 0° C. The resulting mixture was stirred for 2 hr at room temperatureand then concentrated under vacuum; the residue was diluted with 5 mL ofACN and filtered. The crude product was purified by Prep-HPLC with thefollowing conditions (Prep-HPLC-007): Column, SunFire Prep C18 OBDColumn, 150 mm 5 um 10 nm; mobile phase, Water (0.1% formic acid) andMeOH (40% Phase B up to 55% in 7 min, hold 95% in 1 min, down to 40% in1 min, hold 40% in 1 min); Detector, UV. This provided the titlecompound.

¹HTEM NMR (300 MHz, 353K, DMSO-d₆): δ 11.60 (br, 1H), 10.27 (br, 1H),8.60 (dd, J=4.8, 1.8 Hz, 1H), 7.61 (m, 2H), 7.52 (t, J=8.4 Hz, 1H), 7.34(dd, J=7.6, 4.8 Hz, 1H), 6.72 (s, 1H), 6.55 (d, J=8.4 Hz, 1H), 5.16 (s,1H), 4.49 (br, 1H), 4.32 (dd, J=10.3, 6.2 Hz, 1H), 3.21-2.89 (m, 6H),1.91-1.46 (m, 6H). LCMS (ES) [M+1]⁺ m/z 394.1.

Example 4:(S)-2-hydroxy-6-((1-(2-(2-(pyrrolidin-1-yl)ethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde,Compound 4

Compound 4 was synthesized according to Scheme 4.

Step 1: Synthesis of methyl 2-ethenylpyridine-3-carboxylate (4b)

Into a 100-mL round-bottom flask, was placed a mixture of methyl2-chloropyridine-3-carboxylate (3 g, 17.48 mmol, 1.00 equiv), dioxane(40 mL), water (4 mL), 2-ethenyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(5.39 g, 34.99 mmol, 2.00 equiv), Cs₂CO₃ (11.40 g, 34.99 mmol, 2.00equiv) and Pd(PPh₃)₄ (2.02 g, 1.75 mmol, 0.10 equiv). The resultingsolution was stirred for 2 h at 100° C. under N₂. The reaction mixturewas cooled, filtered, and concentrated under vacuum. The resultingresidue was purified by a silica gel column by eluting with ethylacetate/petroleum ether (1/2) to give 2 methyl2-ethenylpyridine-3-carboxylate. LCMS (ES) [M+1]⁺ m/z: 164.1.

Step 2: Synthesis of 2-ethenylpyridine-3-carboxylic acid (4c)

Into a 100-mL round-bottom flask, was placed a solution of methyl2-ethenylpyridine-3-carboxylate (3.0 g, 18.39 mmol, 1 equiv), MeOH (50mL), H₂O (5 mL) and NaOH (3.7 g, 91.93 mmol, 5.0 equiv). After stirringfor 2 h at 50° C., the reaction mixture was cooled, and pH was adjustedto 5 with addition of aqueous HCl (2 M). The resulting mixture wasconcentrated and diluted with 100 mL of DCM. The solids were filteredout. The mixture was concentrated. This resulted in2-ethenylpyridine-3-carboxylic acid. LCMS (ES) [M+1]⁺ m/z: 150.1.

Step 3: Synthesis of tert-butyl(2S)-2-[[(2,2-dimethyl-4-oxo-2,4-dihydro-1,3-benzodioxin-5-yl)oxy]methyl]piperidine-1-carboxylate(4e)

Compound 4d may be synthesized according to methods known in the art.

Into a 1000-mL round-bottom flask, was placed a solution of5-hydroxy-2,2-dimethyl-2,4-dihydro-1,3-benzodioxin-4-one (4d, 10.0 g,51.50 mmol, 1 equiv), THF (300 mL), tert-butyl(2S)-2-(hydroxymethyl)piperidine-1-carboxylate (22.2 g, 103.12 mmol,2.00 equiv) and PPh₃ (40.5 g, 154.49 mmol, 3 equiv). It was added thesolution of diisopropyl azodicarboxylate (“DIAD,” 31.2 g, 154.49 mmol, 3equiv) in THF (30 ml) dropwise at 0° C. under N₂. The resulting solutionwas stirred for 4 h at room temperature. The resulting mixture wasconcentrated. The residue was purified by a silica gel column by elutingwith ethyl acetate/petroleum ether (1/3). This resulted in tert-butyl(2S)-2-[[(2,2-dimethyl-4-oxo-2,4-dihydro-1,3-benzodioxin-5-yl)oxy]methyl]piperidine-1-carboxylate.LCMS (ES) [M+1]⁺ m/z: 392.2.

Step 4: Synthesis of2,2-dimethyl-5-[[(2S)-piperidin-2-yl]methoxy]-2,4-dihydro-1,3-benzodioxin-4-one(4f)

Into a 50-mL round-bottom flask, was placed a solution of tert-butyl(2S)-2-[[(2,2-dimethyl-4-oxo-2,4-dihydro-1,3-benzodioxin-5-yl)oxy]methyl]piperidine-1-carboxylate(2.0 g, 5.10 mmol, 1 equiv), DCM (15 mL) and HCl/dioxane (4 M, 5 mL).The resulting solution was stirred for 1 h at room temperature. Theresulting mixture was concentrated. This resulted in2,2-dimethyl-5-[[(2S)-piperidin-2-yl]methoxy]-2,4-dihydro-1,3-benzodioxin-4-one.LCMS (ES) [M+1]⁺ m/z: 292.2.

Step 5: Synthesis of5-[[(2S)-1-(2-ethenylpyridine-3-carbonyl)piperidin-2-yl]methoxy]-2,2-dimethyl-2,4-dihydro-1,3-benzodioxin-4-one(4g)

Into a 100-mL round-bottom flask, was placed a solution of2,2-dimethyl-5-[[(2S)-piperidin-2-yl]methoxy]-2,4-dihydro-1,3-benzodioxin-4-onehydrochloride (1.0 g, 3.05 mmol, 1 equiv), DCM (50 mL, 786.50 mmol,257.82 equiv), 2-ethenylpyridine-3-carboxylic acid (910.0 mg, 6.10 mmol,2.00 equiv), DIEA (2.0 g, 15.25 mmol, 5 equiv) and HATU (2.3 g, 6.10mmol, 2 equiv) at 0° C. After stirring 2 h at room temperature, thereaction mixture was diluted with 50 mL of DCM and washed with 3×50 mlof brine. The organic layer was dried over anhydrous sodium sulfate andconcentrated. The residue was purified by a silica gel column by elutingwith ethyl acetate/petroleum ether (1/1). This resulted in5-[[(2S)-1-(2-ethenylpyridine-3-carbonyl)piperidin-2-yl]methoxy]-2,2-dimethyl-2,4-dihydro-1,3-benzodioxin-4-one.LCMS (ES) [M+1]⁺ m/z: 423.2.

Step 6: Synthesis of2,2-dimethyl-5-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]pyridine-3-carbonyl]piperidin-2-yl]methoxy]-2,4-dihydro-1,3-benzodioxin-4-one(4h)

Into a 50-mL round-bottom flask, was placed a solution of5-[[(2S)-1-(2-ethenylpyridine-3-carbonyl)piperidin-2-yl]methoxy]-2,2-dimethyl-2,4-dihydro-1,3-benzodioxin-4-one(650 mg, 1.54 mmol, 1 equiv), ethanol (20 mL), pyrrolidine (218.8 mg,3.08 mmol, 2.00 equiv) and TEA (311.4 mg, 3.08 mmol, 2 equiv). Thereaction mixture was stirred for 16 h at 85° C., cooled and concentratedin vacuum. The resulting residue was purified by a silica gel column byeluting with dichloromethane/methanol (10/1). This resulted in2,2-dimethyl-5-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]pyridine-3-carbonyl]piperidin-2-yl]methoxy]-2,4-dihydro-1,3-benzodioxin-4-one.LCMS (ES) [M+1]⁺ m/z: 494.3.

Step 7: Synthesis of2-(hydroxymethyl)-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl]ethyl]pyridine-3-carbonyl]piperidin-2-yl)methoxy]phenol(4i)

Into a 50-mL 3-necked round-bottom flask, was placed a solution of2,2-dimethyl-5-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]pyridine-3-carbonyl]piperidin-2-yl]methoxy]-2,4-dihydro-1,3-benzodioxin-4-one(500 mg, 1.01 mmol, 1 equiv) and THF (10 mL). To this was added lithiumaluminum hydride in THF solution (“LiAlH₄ THF solution,” 2.03 mL, 1 M,2.03 mmol, 2 equiv) dropwise at −78° C. under N₂. The resulting mixturewas stirred at −78° C. for 1 h. The reaction mixture was warmed to 0°C., and then to this was added, dropwise, 0.07 mL of H₂O, 0.07 mL of 15%aqueous NaOH and 0.21 mL of H₂O. The mixture was warmed to roomtemperature and stirred for 30 minutes. The solids were filtered out.The filtrate was concentrated. This resulted in2-(hydroxymethyl)-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]pyridine-3-carbonyl]piperidin-2-yl]methoxy]phenol.LCMS (ES) [M+1]⁺ m/z: 440.3.

Step 8: Synthesis of(S)-2-hydroxy-6-((1-(2-(2-(pyrrolidin-1-yl)ethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde(4)

Into a 50-mL round-bottom flask, was placed a mixture of2-(hydroxymethyl)-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]pyridine-3-carbonyl]piperidin-2-yl]methoxy]phenol(200 mg, 0.46 mmol, 1 equiv), DCM (10 mL) and MnO2 (791.1 mg, 9.10 mmol,20.00 equiv). The resulting mixture was stirred for 1 h at roomtemperature. The reaction mixture was filtered and concentrated. Theresulting residue was purified by reverse phase preparative HPLC(Prep-C18, 5 mM XBridge column, 19×150 mm, waters; gradient elution of15% MeCN in water to 35% MeCN in water over a 6 mM period, where bothsolvents contain 0.1% TFA) to provide2-hydroxy-6-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]pyridine-3-carbonyl]piperidin-2-yl]methoxy]benzaldehyde.¹H NMR (300 MHz, DMSO-d₆) δ 11.57 (s, 1H), 10.26 (s, 1H), 9.48 (s, 1H),8.60 (dd, J=4.8, 1.8 Hz, 1H), 7.65 (s, 1H), 7.53 (t, J=8.3 Hz, 1H), 7.38(dd, J=7.7, 4.8 Hz, 1H), 6.73 (s, 1H), 6.61-6.52 (m, 1H), 4.61-4.41 (m,1H), 4.41-4.25 (m, 1H), 3.60 (t, J=7.2 Hz, 2H), 3.51-2.96 (m, 8H),2.07-1.84 (m, 5H), 1.81-1.36(m, 5H). LCMS (ES) [M+1]⁺ m/z: 438.2.

Example 5:(S)-2-hydroxy-6-((1-(2-(hydroxymethyl)benzoyl)piperidin-2-yl)methoxy)benzaldehyde,Compound 5

Compound 5 was synthesized according to Scheme 5.

In Scheme 5, TBDMSCl refers to tert-butyldimethylsilyl chloride, andMsCl refers to mesyl chloride. Compound 5: MS m/z 370.2 [M+H]⁺, 392.2[M+Na]⁺.

Example 6:(R)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehydeand(S)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehyde

Step 1: Synthesis of[4-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol(6a)

Into a 100-mL 3-necked round-bottom flask, was addded2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carboxylic acid(2.00 g, 7.11 mmol, 1.00 equiv), thiomorpholin-3-ylmethanol (0.95 g,7.13 mmol, 1.00 equiv), DIEA (2.76 g, 21.32 mmol, 3.00 equiv) and DCM(30.00 mL). To this mixture was added HATU (3.24 g, 8.53 mmol, 1.20equiv), in portions at 0° C. The resulting reaction mixture was allowedto warm to room temperature and stirred for overnight. The reaction wasthen quenched by the addition of 30 mL of water. The resulting solutionwas extracted with 3×30 mL of dichloromethane and the organic layerswere separated, combined and dried over anhydrous sodium sulfate andconcentrated. The residue was applied onto a silica gel column withTHF/petroleum ether (“PE”) (30%) as eluent. The combined fractions wereconcentrated to produce[4-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol.LCMS (ES) [M+H]+m/z: 397.

Step 2. Synthesis of2-[[4-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(6b)

Into a 100-mL 3-necked round-bottom flask, was added[4-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol(1.50 g, 3.78 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.63 g, 4.56mmol, 1.21 equiv), PPh₃ (1.19 g, 4.54 mmol, 1.20 equiv), and DCM (30.00mL). To this solution was added DIAD (0.92 g, 4.54 mmol, 1.20 equiv)dropwise over 20 mins with stirring at 0° C. The resulting mixture wasstirred overnight at room temperature, and was concentrated. The residuewas directly applied onto a silica gel column with THF/PE (25%) aseluent. The combined fractions were concentrated to give2-[[4-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+H]+ m/z:517.

Step 3. Chiral-HPLC separation of Compound 6b

The racemate was purified by Chiral-HPLC to give Enantiomer 1 andEnantiomer 2 of Compound 6b with the following conditions: Column, LuxCellulose-4, 4.6*100 mm, 3 μm; mobile phase, A: n-Hexane B: Ethanol (35%B in 18 min); Flow rate: 30 mL/min; Detector, 254. LCMS (ES) [M+H]+m/z:517 (for both compounds).

Step 4a. Removal of TBS group to give Compound 10, Enantiomer 1

HCl (˜2M) in 5 ml of ethyl acetate (“EA”) was added to Enantiomer 1 ofCompound 6b (335.00 mg, 0.65 mmol, 1.00 equiv) in EA (3.00 mL) dropwisewith stirring at 0° C. The resulting solution was stirred for 2 h atroom temperature. The pH value of the solution was adjusted to 8 withsaturated NaHCO₃. The resulting solution was extracted with 3×10 mL ofethyl acetate and the organic layers combined, dried over anhydroussodium sulfate, filtered and concentrated. The crude product waspurified by Prep-HPLC with the following conditions: Column, XBridgePrep C18 OBD Column, 19 cm, 150 mm, 5 um; mobile phase, Water (0.1%HCOOH) and CAN (30% Phase B up to 40% in 10 min); Detector, 254. Thisresulted in Enantiomer 1 of Compound 10 with retention time=4.06 min.LCMS (ES) [M+H]⁺ m/z: 403.1; [M+Na]⁺ m/z: 425.1.

Step 4b. Removal of TBS group to give Compound 10, Enantiomer 2

HCl (˜2M) in 5 ml of EA was added to Enantiomer 2 of Compound 6b (335.00mg, 0.65 mmol, 1.00 equiv) in EA (3.00 mL) dropwise with stirring at 0°C. The resulting solution was stirred for 2 h at room temperature. ThepH value of the solution was adjusted to 8 with saturated NaHCO₃. Theresulting solution was extracted with 3×10 mL of ethyl acetate and theorganic layers combined, dried over anhydrous sodium sulfate, filteredand concentrated. The crude product (200 mg) was purified by Prep-HPLCwith the following conditions: Column, XBridge Prep C18 OBD Column, 19cm, 150 mm, 5 um; mobile phase, Water (0.1% HCOOH) and CAN (30% Phase Bup to 40% in 10 min); Detector, 254. This resulted in Enantiomer 2 ofCompound 10 with retention time=5.40 min. LCMS (ES) [M+H]⁺ m/z: 403.2;[M+Na]⁺ m/z: 425.1.

Alternative Synthesis of(R)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehyde

(R)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehydecan be made directly from chiral (R)-thiomorpholin-3-ylmethanol asdepicted in Scheme 6B.

Step 1

To a solution of L-cysteine (100.0 g, 825.4 mmol, 1.0 equiv) in H₂O (1.0L) was added NaOH (3.3 g, 82.5 mmol, 0.1 equiv). After the reactionmixture was cooled to 0° C., ethylene oxide (100.0 g, 2.26 mol, 2.75equiv) was added dropwise. The resulting solution was stirred for 3 hrat 0-25° C. in a water/ice bath. The resulting solution was extractedwith 3×500 mL of ethyl acetate to remove unchanged ethylene oxide. Theaqueous layer was concentrated under reduced pressure. The crude productwas triturated with EtOH (200 mL) for lh and filtered. This resulted inhydroxyethylcysteine. LCMS (ES) [M+1]⁺ m/z: 166.2; Retention time 0.174min ¹H-NMR: (300 MHz, D₂O, ppm): δ 3.83 (dd, J=3.0, 6.0 Hz, 1H), 3.67(t, J=6.0, 2H), 3.04(dd, J=14.8, 4.4 Hz, 1H), 2.97 (dd, J=14.8, 7.4 Hz,1H), 2.68 (t, J=6.0, 2H).

Step 2

To a mixture of hydroxyethylcysteine (130.0 g, 786.8 mmol, 1.0 equiv)and KHCO₃ (165.4 g, 1.65 mol, 2.1 equiv) in dioxane (700 mL, 8.26 mol,10.5 equiv) and H₂O (700 mL) was added CbzCl (147.6 g, 865 mmol, 1.1equiv) dropwise at 0° C. over 30 min. The resulting solution was stirredfor 5 h at 0-25° C. The solvents evaporated off and the residuedissolved in DMF (1000 mL). BnBr (148 g, 0.86 mol, 1.1 equiv) was addedand the resulting mixture was stirred for 16 h at 0-25° C. The reactionwas then quenched by the addition of 1000 mL of water. The resultingsolution was extracted with 3×1000 mL of EtOAc, the combined organiclayer was washed with brine, dried over anhydrous sodium sulfate andconcentrated under vacuum. The residue was applied onto a silica gelcolumn with ethyl acetate/petroleum ether (1:50 to 1:5). This resultedin benzyl(2R)-2-[[(benzyloxy)carbonyl]amino]-3-[(2-hydroxyethyl)sulfanyl]propanoate.LCMS (ES) [M+1]⁺ m/z: 390.5; Retention time 1.146 min, ¹H-NMR: (300 MHz,CDCl₃, ppm): δ 7.39-7.33 (m, 10H), 5.83 (br, 1H), 5.26 (d, J=4.7 Hz,2H), 5.17(s, 2H), 4.71-4.65 (m, 1H), 3.69-3.63(m, 2H), 3.09-2.98 (m,2H), 2.71-2.61 (m, 2H).

Step 3

Into a 2500-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of argon, was placed benzyl(2R)-2-[[(benzyloxy)carbonyl]amino]-3-[(2-hydroxyethyl)sulfanyl]propanoate(90.0 g, 231 mmol, 1.0 equiv), THF (1.0 L), DEAD (48.3 g, 277 mmol, 1.2equiv). After the reaction was cooled to 0° C., PPh₃ (78.8 g, 300 mmol,1.3 equiv) in THF (100 mL) was added dropwise. The resulting solutionwas stirred for 16 h at 0-25° C. The resulting mixture was concentrated.The residue was applied onto a silica gel column with THF/PE (1:100 to1:5). This resulted in 3,4-dibenzyl(3R)-thiomorpholine-3,4-dicarboxylate. LCMS (ES) [M+1]⁺ m/z: 372.1;Retention time 1.312 min.

Step 4

Into a 2500-mL 3-necked round-bottom flask, was placed 3,4-dibenzyl(3R)-thiomorpholine-3,4-dicarboxylate (100.0 g, 269 mmol, 1.0 equiv),DCM (1.0 L). The reaction was cooled to 0° C., TMSI (161.6 g, 0.81 mol,3 equiv) was added dropwise. The resulting solution was stirred for 1 hat 0-25° C. in a water/ice bath. The reaction was then quenched by theaddition of 100 mL of MeOH. The resulting mixture was concentrated. ThepH value of the solution was adjusted to 1 with HCl (2 mol/L). Theresulting solution was extracted with 2×500 mL of MTBE, and the aqueouslayers were combined. NaHCO₃ (2 mol/L) was employed to adjust the pH to8. The resulting solution was extracted with 3×500 mL of ethyl acetate.The combined organic layer was dried over Na₂SO₄ and concentrated underreduced pressure. This resulted in benzyl(3R)-thiomorpholine-3-carboxylate. LCMS (ES) [M+1]⁺ m/z: 238.1;Retention time 1.026 min; ¹H-NMR: (300 MHz, CDCl₃, ppm): δ 7.43-7.33 (m,5H), 5.25 (s, 2H), 3.74 (dd, J=8.6, 3.4 Hz, 1H), 3.40 (ddd, J=12.5, 4.9,3.0 Hz, 1H), 3.04 (ddd, J=12.5, 9.8, 2.7 Hz, 1H), 2.90 (ddd, J=13.2,3.4, 1.3 Hz, 1H), 2.82 (dd, J=13.3, 8.6 Hz, 1H), 2.70 (ddd, J=12.9, 9.8,3.0 Hz, 1H), 2.48 (dddd, J=13.3, 4.9, 2.7, 1.3 Hz, 1H).

Step 5

To a suspension of LiAlH₄ (13.2 g, 347 mmol, 1.5 equiv) in THF (1000 mL)was added benzyl (3R)-thiomorpholine-3-carboxylate (55.0 g, 231.7 mmol,1.0 equiv) in THF (100 mL) drop wise at 0° C. After the resultingsolution was stirred for 3 hr at 0-25° C., the reaction was thenquenched by the addition of 100 g of Na₂SO₄.10H₂O. The resultingsolution was diluted with 500 mL of THF, and the solids were filteredout. The resulting mixture was concentrated, and the residue was appliedonto a silica gel column with THF/PE (1:50 to 2:1). This resulted in(3R)-thiomorpholin-3-ylmethanol. LCMS (ES) [M+1]⁺ m/z: 134.1; Retentiontime 0.464 min; ¹H-NMR: (300 MHz, DMSO-d6, ppm): δ 4.64 (br, 1H),3.26-3.17 (m, 2H), 2.81-2.68 (m, 4H), 2.43-2.26 (m, 4H).

Step 6

Into a 300-mL 3-necked round-bottom flask, was placed2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carboxylic acid(20.00 g, 71.06 mmol, 1.00 equiv), (3R)-thiomorpholin-3-ylmethanol(10.41 g, 78.14 mmol, 1.10 equiv), DCM (300.00 mL), and DIEA (18.37 g,142.13 mmol, 2.00 equiv). This was followed by the addition of HATU(32.43 g, 85.28 mmol, 1.20 equiv), in portions at 0° C. The resultingsolution was stirred for 3 h at room temperature. The reaction was thenquenched by the addition of 200 mL of water. The resulting solution wasextracted with 3×200 mL of dichloromethane, and the organic layers werecombined and dried over anhydrous sodium sulfate and concentrated. Theresidue was applied onto a silica gel column with THF/PE (30%). Thisresulted in[(3R)-4-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol.LCMS (ES) [M+H]⁺ m/z: 397.30.

Step 7

Into a 1000-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed 2,6-dihydroxybenzaldehyde (7.52g, 54.45 mmol, 1.20 equiv),[(3R)-4-(2-[2-[tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol(18.00 g, 45.38 mmol, 1.00 equiv), PPh₃ (14.28 g, 54.46 mmol, 1.20equiv), and DCM (400.00 mL). This was followed by the addition of DIAD(11.01 g, 54.46 mmol, 1.20 equiv) dropwise with stirring at 0° C. Theresulting solution was stirred for overnight at room temperature. Theresulting mixture was concentrated. The residue was applied onto asilica gel column with THF/PE (15%). This resulted in2-[[(3R)-4-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+H]⁺ m/z: 517.35.

Step 8

Into a 500-mL round-bottom flask, was placed2-[[(3R)-4-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(13.50 g, 26.13 mmol, 1.00 equiv) and EA (20.00 mL). To the above HC1(g)in EA (52.25 mL, 104.50 mmol, 4.00 equiv) was introduced in dropwisewith stirring at 0° C. The resulting solution was stirred for 2 h atroom temperature. The reaction was then quenched by the addition of 80mL of water. The pH value of the solution was adjusted to 7-8 withsaturated Na₂CO₃. The resulting solution was extracted with 3×100 mL ofdichloromethane, and the organic layers combined and dried in an ovenunder reduced pressure, and concentrated. The crude product was purifiedby Prep-HPLC with the following conditions: Column, XBridge Prep C18 OBDColumn, 19 cm, 150 mm, 5 um; mobile phase, Water (0.1% HCOOH) and ACN(30% Phase B up to 50% in 11 min); Detector, 254. This resulted in2-hydroxy-6-[[(3R)-4-[2-(2-hydroxyethyl)pyridine-3-carbonyl]thiomorpholin-3-yl]methoxy]benzaldehyde.

Chiral HPLC conditions were as follows: Instrument: SHIMADZU LC-20AT;Mobile Phase A: n-Hexane(0.1% TFA); Mobile Phase B: Ethanol; Conc. ofPhase B: 50.0%; Flow Rate: 1.000 mL/min; Column: Lux Cellulose-4,4.6*100 mm, 3 μm. Chiral HPLC retention time=5.41 min.

LCMS (ES, m/z): [M+H]⁺: 403.2; ¹H NMR (300 MHz, DMSO-d6): δ 11.80-11.73(m, 1H), 10.33 (br, 1H), 8.56 (dd, J=4.9, 1.8 Hz, 1H), 7.90-7.39 (m,2H), 7.37-7.19 (m, 1H), 6.81-6.63 (m, 1H), 6.56 (d, J=8.4 Hz, 1H),5.49-4.60 (m, 1H), 4.60-4.05 (m, 2H), 3.88-3.36 (m, 4H), 3.20-2.61 (m,6H), 2.43 (d, J=12.6 Hz, 1H).

Based on the product of Scheme 6B, it was determined that Compound 10,Enantiomer 2 corresponds to(R)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehyde.

Example 7:(S)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde,Compound 8

Compound 8 was synthesized according to Scheme 7.

Step 1: Synthesis of(R)-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone (7a)

To a solution of2[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carboxylic acid (1.50g, 5.33 mmol, 1.00 equiv) and (3R)-morpholin-3-ylmethanol hydrochloride(0.98 g, 6.39 mmol, 1.20 equiv) in DCM (20 mL) was added DIEA (2.07 g,15.99 mmol, 3.00 equiv), followed by the addition of HATU (2.43 g, 6.39mmol, 1.20 equiv) in portions over 5 mins. The resulting solution wasstirred for 2 hr at room temperature, diluted with 50 mL of H₂O. Theresulting solution was extracted with 2×30 mL of dichloromethane and theorganic layers were separated, combined, dried over anhydrous sodiumsulfate, and filtered. The filtrate was concentrated to give a residuethat was purified on silica gel column with ethyl acetate/petroleumether (2/1) as eluent. This resulted in(R)-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone. LCMS (ES) [M+H]⁺ m/z: 381.2.

Step 2. Synthesis of(S)-2-((4-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)nicotinoyl)morpholin-3-yl)methoxy)-6-hydroxybenzaldehyde(7b)

A solution of(R)-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone (600 mg, 1.57 mmol, 1.00 equiv),2,6-dihydroxybenzaldehyde (261 mg, 1.89 mmol, 1.20 equiv), and PPh₃ (496mg, 1.89 mmol, 1.20 equiv) in DCM (10 mL) was purged and maintained withan inert atmosphere of nitrogen. To this mixture was added DIAD (382 mg,1.89 mmol, 1.20 equiv) dropwise with stirring at 0° C. over 5 min. Theresulting solution was stirred for 1 hr at room temperature, dilutedwith 20 mL of H₂O. The resulting solution was extracted with 2×20 mL ofdichloromethane and the organic layers combined, dried over anhydroussodium sulfate, and filtered. The filtrate was concentrated to give thecrude product which was purified by Flash-Prep-HPLC with the followingconditions (IntelFlash-1): Column, C18 silica gel; mobile phase, H₂O(0.1% HCOOH)/acetonitrile (“ACN”)=2/1 increasing to H₂O (0.1%HCOOH)/ACN=1/4 within 18 min; Detector, UV 254 nm. This resulted in(S)-2-((4-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)nicotinoyemorpholin-3-yl)methoxy)-6-hydroxybenzaldehyde.LCMS (ES) [M+H]⁺ m/z: 501.2.

Step 3. Synthesis of(S)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde (8)

Formic acid (HCOOH, 1 ml) was added to a solution of(S)-2-((4-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)nicotinoyl)morpholin-3-yl)methoxy)-6-hydroxybenzaldehyde(450 mg, 0.89 mmol, 1.00 equiv) in ACN (5.00 mL). The resulting solutionwas stirred for 3 hr at 40° C., cooled room temperature and diluted with5 mL of ACN. The mixture was concentrated to give the crude product,which was purified by Prep-HPLC with the following conditions(2#SHIMADZU (HPLC-01)): Column, Atlantis HILIC OBD Column, 19*150 mm*5um; mobile phase, Water(0.1% FA) and ACN (37% PhaseB up to 45% in 10min); Detector, UV 254 nm. This resulted in(S)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde. LCMS (ES) [M+H]⁺ m/z: 387.1.

Example 8.(S)-2-hydroxy-6-((1-(2-(hydroxymethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde,Compound 11

Compound 11 was synthesized according to Scheme 8.

Step 1: Synthesis of 3-(methoxycarbonyl)-2-methylpyridine 1-oxide

To a solution of methyl 2-methylpyridine-3-carboxylate (15.00 g, 99.23mmol, 1.0 equiv) in DCM (150 mL) at 0° C. was added 3-chloroperbenzoicacid (“m-CPBA,” 34.4 g, 199.34 mmol, 2.0 equiv). The reaction mixturewas stirred for 2 h at room temperature. The reaction was quenched withsaturated aqueous Na₂CO₃ (100 mL), and the organic phase was separatedout and dried over anhydrous sodium sulfate. The solution was filtered,and the filtrate was concentrated under reduced pressure. The residuewas purified by silica gel column with dichloromethane/methanol (10/1),providing 3-(methoxycarbonyl) methylpyridine 1-oxide. LCMS (ES) [M+H]⁺m/z: 168.

Step 2. Synthesis of methyl 2-(acetoxymethyl)nicotinate

A mixture of 3-(methoxycarbonyl)-2-methylpyridine 1-oxide (8.00 g) inacetic anhydride (80 mL) was heated for 5 h at 140° C. After beingcooled to room temperature, excess liquid was removed under reducedpressure, and the residue was suspended in water (50 mL) and extractedwith 3×50 mL of dichloromethane. The combined organic phase was driedover anhydrous sodium sulfate and filtered, and the filtrate wasconcentrated under reduced pressure. The residue was purified by silicagel column with ethyl acetate/petroleum ether (15%), providing methyl2-(acetoxymethyl)nicotinate. LCMS (ES) [M+H]⁺ m/z: 210.

Step 3. Synthesis of methyl 2-(hydroxymethyl)nicotinate

To a solution of methyl 2-(acetoxymethyl)nicotinate (7.90 g, 37.76 mmol,1.0 equiv), in MeOH (80 mL) was added acetyl chloride (3.60 g, 45.86mmol, 1.2 equiv). The reaction solution was stirred overnight at roomtemperature; then, the solvent was removed under reduced pressure, andthe resulting residue was dissolved in water (20 mL). The pH wasadjusted to 8 with NaHCO₃ solid and extracted with ethyl acetate (30mL*3). The combined organic phase was dried over anhydrous sodiumsulfate and filtered, and the filtrate was concentrated in vacuum. Theresidue was purified by silica gel column with ethyl acetate/petroleumether (1/1), giving methyl 2-(hydroxymethyl)pyridine-3-carboxylate. LCMS(ES) [M+1]⁺ m/z: 168.

Step 4. Synthesis of methyl2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinate

Into a 100-mL 3-necked round-bottom flask, was placed methyl2-(hydroxymethyl)pyridine-3-carboxylate (2.80 g, 16.75 mmol, 1.0 equiv),DCM (40 mL), and imidazole (2.27 g, 33.34 mmol, 2.0 equiv). This wasfollowed by the addition of t-butyldimethylchlorosilane (4.04 g, 26.81mmol, 1.6 equiv) at 0° C. The mixture was stirred for 2 h at roomtemperature. The reaction was then quenched by the addition of water (30mL), extracted with 3×50 mL of dichloromethane. The combined organicphase was dried over anhydrous sulfate and filtered, and the filtratewas concentrated in vacuum. The residue was purified by silica gelcolumn with ethyl acetate/petroleum ether (10%), giving methyl2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinate. LCMS (ES) [M+1]⁺m/z: 282.

Step 5. Synthesis of 2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinicacid

Into a 100-mL 3-necked round-bottom flask, was placed methyl2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinate (4.20 g, 14.92 mmol,1.0 equiv), MeOH (30 mL), and H₂O (15 mL). This was followed by theaddition of LiOH H₂O (1.25 g, 29.79 mmol, 2.0 equiv) at 0° C. Themixture was stirred for 2 h at room temperature, then concentrated toremove the solvent, and the pH value of the residue was adjusted to 7with citric acid. The solution was filtered, and the solid was driedunder infrared lamp. 2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinicacid was obtained. LCMS (ES) [M+1]⁺ m/z: 268.

Step 6. Synthesis of(S)-(2-(((tert-butyldimethylsilyl)oxy)methyl)pyridin-3-yl)(2-(hydroxymethyl)piperidin-1-yl)methanone

Into a 50-mL 3-necked round-bottom flask, was placed2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinic acid (615 mg, 2.30mmol, 1.0 equiv), (2S)-piperidin-2-ylmethanol (318 mg, 2.76 mmol, 1.2equiv), DCM (10 mL), DIEA (594 mg, 4.60 mmol, 2.0 equiv). This wasfollowed by the addition of HATU (1.05 g, 2.76 mmol, 1.2 equiv) at 0° C.The mixture was stirred for 2 h at room temperature. The reactionmixture was concentrated to remove solvent, and the residue was purifiedby silica gel column with ethyl acetate/petroleum ether (80%).(S)-(2-(((tert-butyldimethylsilyl)oxy)methyl)pyridin-3-yl)(2-(hydroxymethyl)piperidin-1-yl)methanonewas obtained. LCMS (ES) [M+1]⁺ m/z: 365.

Step 7. Synthesis of(S)-2-((1-(2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinoyl)piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde

Into a 40-mL vial purged and maintained with an inert atmosphere ofnitrogen, was placed(S)-(2-(((tert-butyldimethylsilyl)oxy)methyl)pyridin-3-yl)(2-(hydroxymethyl)piperidin-1-yl)methanone(316 mg, 0.87 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (143 mg, 1.04mmol, 1.2 equiv), PPh₃ (340 mg, 1.30 mmol, 1.5 equiv), and THF (15 mL).This was followed by the addition of DIAD (262 mg, 1.30 mmol, 1.5 equiv)at 0° C. After addition, the reaction solution was stirred overnight atroom temperature and then concentrated to remove solvent. The resultingresidue was purified by silica gel column with ethyl acetate/petroleumether (1/1).(S)-2-((1-(2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinoyepiperidin-2-yl)methoxy)-6-hydroxybenzaldehydewas obtained. LCMS (ES) [M+1]⁺ m/z: 485.

Step 8. Synthesis of(S)-2-hydroxy-6-((1-(2-(hydroxymethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehyde

Into a 50-mL round-bottom flask, was placed(S)-2-((1-(2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinoyl)piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde(250 mg, 0.52 mmol, 1.0 equiv) in EA (3 ml). To the above solution wasadded HCl(g) (2 M in EA) (5.0 mL) was added at 0° C., the mixture wasallowed to stir for 1 h at room temperature. The reaction was thendiluted by the addition of water (20 mL), and the pH value of thesolution was adjusted to 8 with NaHCO₃ solid and extracted with 3×20 mLof ethyl acetate. The combined organic phase was concentrated underreduced pressure, and the residue was purified by Prep-HPLC withconditions: (2#SHIMADZU (HPLC-01)): Column, Kinetex EVO C18 Column,21.2*150, 5 um, mobile phase, Water (0.1% Formic Acid) and CH₃CN (10%Phase B up to 90% within 15 min), detector, UV 254 nm.(S)-2-hydroxy-6-((1-(2-(hydroxymethyl)nicotinoyl)piperidin-2-yl)methoxy)benzaldehydewas obtained. LCMS-PH− (ES, m/z): [M+H]⁺: 371.1; [M+Na]⁺: 393.1.

Example 9.(S)-2-hydroxy-6-((4-(2-(hydroxymethyl)nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde,Compound 12

Compound 12 was synthesized according to Scheme 9A.

Step 1: Synthesis of(R)-(2-(((tert-butyldimethylsilyl)oxy)methyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone

To a solution of2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carboxylic acid (530mg, 1.98 mmol, 1.0 equiv), (3R)-morpholin-3-ylmethanol hydrochloride(364 mg, 2.38 mmol, 1.2 equiv), and DIEA (768 mg, 5.94 mmol, 3.0 equiv)in DCM (10 mL) was added HATU (905 mg, 2.38 mmol, 1.2 equiv) at 0° C.The reaction solution was stirred for 3 h at room temperature. Thesolution was then concentrated to remove the solvent, and the residuewas purified by silica gel column with ethyl acetate/petroleum ether(60%).(R)-(2-(((tert-butyldimethylsilyl)oxy)methyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanonewas obtained. LCMS (ES) [M+1]⁺ m/z: 367.

Step 2. Synthesis of(S)-2-((4-(2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinoyl)morpholin-3-yl)methoxy)-6-hydroxybenzaldehyde

Into a 40-mL vial purged and maintained with an inert atmosphere ofnitrogen, was placed(R)-(2-(((tert-butyldimethylsilyl)oxy)methyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone(630 mg, 1.72 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (284 mg, 2.06mmol, 1.2 equiv), PPh₃ (540 mg, 2.06 mmol, 1.2 equiv), THF (20 mL). Thiswas followed by the addition of DBAD (474 mg, 2.06 mmol, 1.2 equiv) at0° C. The reaction solution was stirred overnight at room temperature.The solution was concentrated in vacuum to remove the solvent, and theresidue was purified by silica gel column with ethyl acetate/petroleumether (1/1).(S)-2-((4-(2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinoyemorpholin-3-yl)methoxy)-6-hydroxybenzaldehydewas obtained. LCMS (ES) [M+1]⁺ m/z: 487.

Step 3. Synthesis of(S)-2-hydroxy-6-((4-(2-(hydroxymethyl)nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde

Into a 25-mL round-bottom flask, was placed(S)-2-((4-(2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinoyl)morpholin-3-yl)methoxy)-6-hydroxybenzaldehyde(380 mg, 0.78 mmol, 1.0 equiv). To the above, HCl (g) (2 M) in EA (5 mL)was added at 0° C. The reaction solution was stirred for 1 h at roomtemperature. The reaction was then quenched by the addition of water (10mL), and the pH value of the solution was adjusted to 8 with NaHCO₃solid and extracted with 3×10 mL of ethyl acetate. The combined organicphase was dried over anhydrous sodium sulfate and filtered, and thefiltrate was concentrated under reduced pressure. The crude product waspurified by Prep-HPLC with the following conditions (2#SHIMADZU(HPLC-01)): Column, Kinetex EVO C18 Column, 21.2*150, 5 um, mobilephase, Water (0.1% Formic Acid) and CH₃CN (10% Phase B up to 50% within15 min), detector, UV 254 nm.(S)-2-hydroxy-6-((4-(2-(hydroxymethyl)nicotinoyl)morpholin-3-yl)methoxy)benzaldehydewas obtained. LCMS: (ES, m/z): [M+H]⁺: 373.1; [M+Na]⁺: 395.1.

Alternative Synthesis: Scheme 9B.

Alternatively, Compound 12 can be synthesized as shown in Scheme 9Busing similar procedures described in Scheme 9A.

Compound 9c can be converted into 9d using methods known in the art (forexample, sodium tetrahydroborate; acetic acid in tetrahydrofuran at 15°C.; for 4 h). Then, using a silyl protecting group such as TBDPS(tert-butyldiphenylsilyl), intermediate 8e2 can be converted intocompound 12 using similar conditions as described in Scheme 9A.

Example 10.(S)-2-hydroxy-6-((4-(2-(hydroxymethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehydeand(R)-2-hydroxy-6-((4-(2-(hydroxymethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehyde

Step 1. Synthesis of(2-(((tert-butyldimethylsilyl)oxy)methyl)pyridin-3-yl)(3-(hydroxymethyl)thiomorpholino)methanone

To a solution of2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carboxylic acid (1.20g, 4.50 mmol, 1.00 equiv) and thiomorpholin-3-ylmethanol hydrochloride(912 mg, 5.40 mmol, 1.20 equiv) in DMF under nitrogen at 0° C. was addedDIEA (909 mg, 9.00 mmol, 2.00 equiv). This was followed by the additionof HATU (2.05 g, 5.40 mmol, 1.20 equiv) in several batches at 0° C. Themixture was allowed to slowly warm to room temperature and stirred for16 h. The reaction was diluted with water (100 mL) and extracted with3×100 mL of ethyl acetate. The combined organic layer was washed with3×50 mL of brine, dried over anhydrous sodium sulfate, and concentrated.The residue was applied onto a silica gel column and eluted with ethylacetate/petroleum ether (from 0% to 100% ethyl acetate). Removal of thesolvents produced[4-(2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 383.

Step 2. Synthesis of2-((4-(2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinoyl)thiomorpholin-3-yl)methoxy)-6-hydroxybenzaldehyde

To a mixture of[4-(2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol(1.20 g, 3.14 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (519 mg, 3.76mmol, 1.20 equiv), and PPh₃ (0.99 g, 3.76 mmol, 1.20 equiv) in THF (50.0mL) under nitrogen at 0° C. was added a solution of DBAD (0.87 g, 3.76mmol, 1.20 equiv) in THF (1 mL) dropwise over 15 min The resultingmixture was stirred for 16 h at room temperature. The reaction mixturewas concentrated to remove solvents, and the residue was applied onto asilica gel column, eluted with ethyl acetate/petroleum ether (1:0).After removing solvents, this produced2-[[4-(2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z: 503.

Step 3. Chiral-HPLC separation of Compound 10b.

Racemic2-[[4-(2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehydewas purified by Chiral-Prep-HPLC with the following conditions: AgelaHP-Flash (model: HP-1000); Mobile phase: A:n-Hexane/DCM=5/1; B:Ethanol;Flow rate: 30 mL/min; Column: CHIRALPAK IG-3, 4.6*50 mm, 3 μm; andGradient:20% B in 15 min; 220 nm.

This resulted in each of Enantiomers 1 and 2 of Compound 10b (Rt=10 minand 12 min, respectively). LCMS (ES) [M+1]⁺ m/z: 503.

Step 4a. Removal of TBS group to give Compound 13, Enantiomer 1

To a solution of Enantiomer 1 of Compound 10b (119 mg, 0.24 mmol, 1.00equiv) in THF (10.0 mL) was added triethylamine trihydrofluoride(“TEA.3HF”) (458 mg, 2.84 mmol, 12.0 equiv). The reaction was stirredfor 16 h at room temperature. Solvents were removed, and the residue wasapplied onto a C18 silica gel column with Phase A: Water/0.05% TFA,Mobile Phase B: Acetonitrile; Flow rate: 1.5 mL/min; Gradient: 5% B to100% B in 1.2 min, hold 0.6 min. This resulted in Compound 13,Enantiomer 1. RT=3.614 mins; LCMS (ES, m/z): [MH]⁺ 389.1.

Step 4b. Removal of TBS group to give Compound 13, Enantiomer 2

To a solution of Enantiomer 2 of Compound 10b (120 mg, 0.24 mmol, 1.00equiv) in THF (10.0 mL) was added TEA.3HF (461 mg, 2.87 mmol, 12.0equiv). The mixture was stirred for 16 h at room temperature. Solventswere removed, and the residue was applied onto a C18 silica gel columnwith Phase A: Water/0.05% TFA, Mobile Phase B: Acetonitrile; Flow rate:1.5 mL/min; Gradient: 5% B to 100% B in 1.2 min, hold 0.6 min. Thisresulted in Compound 13, Enantiomer 2. RT=4.387 mins; LCMS (ES, m/z):[MH]⁺ 389.1; [MNa]⁺ 411.1.

Alternative synthesis of(R)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehyde

Alternatively,(R)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehydecan be made directly from chiral (R)-thiomorpholin-3-ylmethanol asdepicted in Scheme 10B.

Step 1

Into a 2-L three-necked round-bottom flask, was placed a solution of(3-bromopyridin-2-yl)methanol (50 g, 0.267 mol, 1.0 equiv) in DCM (1.0L) and 1H-imidazole (36.4 g, 0.534 mol, 2.0 equiv). After the mixturewas cooled to 0° C., tert-butyl(chloro)dimethylsilane (48.1 g, 0.320mol, 1.2 equiv) was added by three batches. The reaction solution waswarmed to room temperature and stirred for 4 h. The reaction mixture wasdiluted with H₂O (1.0 L) and extracted with 2×500 mL of DCM. Thecombined organic phase was dried over anhydrous sodium sulfate andfiltered. The filtrate was concentrated under reduced pressure, and theresidue was purified by silica gel column with ethyl acetate/petroleumether (1:10) to provide the title compound. LCMS (ES) [M+1]⁺ m/z 302.d

Step 2

Into a 2-L three-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed a solution of3-bromo-2-(((tert-butyldimethylsilyl)oxy)methyl)pyridine (70.0 g, 0.233mol, 1.0 equiv) in THF (700 mL). This was followed by the addition ofn-BuLi (2.5 M in hexane) (102.5 mL, 0.256 mol, 1.1 equiv) dropwise withstirring at −78° C. After addition, the mixture was stirred for 0.5 h,and ethyl carbonochloridate (37.8 g, 0.350 mol, 1.5 equiv) was added atthe same temperature and stirred for 1 h. The reaction was then quenchedby the addition of 500 mL of aqueous NH₄Cl and extracted with 2×600 mLof ethyl acetate. The combined organic phase was dried over anhydroussodium sulfate and filtered, and the filtrate was concentrated underreduced pressure. The residue was purified by silica gel column withethyl acetate/petroleum ether (1:4) to provide the title compound. LCMS(ES) [M+1]⁺ m/z 296.

Step 3

Into a 1-L three-necked round-bottom flask, was placed ethyl2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinate (38.6 g, 0.131 mol,1.0 equiv), MeOH (400 mL), and H₂O (200 mL). This was followed by theaddition of LiOH H₂O (11.0 g, 0.262 mol, 2.0 equiv) at 0° C. The mixturewas stirred for 2 h at room temperature. The mixture was concentrated toremove the solvent, and the pH value of the residue was adjusted to 7with citric acid. The solution was filtered, and the solid was driedunder infrared lamp. 2-(((tert-butyldimethylsilyl)oxy)methyl)nicotinicacid was obtained. LCMS (ES) [M+1]⁺ m/z: 268.

Step 4

Compound 6h was prepared as described in Scheme 6B. To a solution of2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carboxylic acid (10.0g, 37.3 mmol, 1.0 equiv), DIPEA (12.1 g, 93.5 mmol, 2.5 equiv) and HATU(17.06 g, 44.877 mmol, 1.20 equiv) in DMF (100 mL) was added(3R)-thiomorpholin-3-ylmethanol (4.98 g, 37.397 mmol, 1.00 equiv) at 0°C. in portions. The resulting solution was stirred for 4 hr at 0-25° C.The reaction was then quenched by the addition of 200 mL of water. Theresulting solution was extracted with 3×200 mL of ethyl acetate, driedover anhydrous sodium sulfate, and concentrated under vacuum. Theresidue was applied onto a silica gel column with ethylacetate/petroleum ether (1:100 to 1:10). This resulted in[(3R)-4-(2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 383.2; Retention time 1.138 min. ¹H-NMR: (300 MHz,CDCl3, ppm): δ 8.60 (dd, J=4.8,1.5 Hz, 1H), 7.67-7.53 (m, 1H), 7.29-7.25(m, 1H), 5.37-4.90 (m, 2H), 4.86-4.74 (m, 1H), 4.38-4.22 (m, 1H),3.90-3.61 (m, 1H), 3.58-3.42 (m, 2H), 3.25-3.12 (m, 1H), 2.94-2.39 (m,4H), 0.96-0.88 (m, 9H), 0.21-0.01(m, 6H).

Step 5

A solution of[(3R)-4-(2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol(11.0 g, 28.7 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (4.7 g, 34.5mmol, 1.2 equiv) and PPh3 (9.8 g, 37.3 mmol, 1.3 equiv) in DCM (1.1 L)was cooled to 0° C. under Ar atmosphere. A solution of DBAD (7.28 g,230.2 mmol, 1.1 equiv) in DCM (100 mL) was added dropwise. The resultingsolution was stirred for 16 hr at 0-25° C. The reaction was concentratedunder vacuum. The residue was applied onto a silica gel column withethyl acetate/petroleum ether (1:100 to 1:5).This resulted in2-[[(3R)-4-(2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1] m/z: 503.2; Retention time 1.223 min ¹H-NMR: (300 MHz,DMSO-d₆, ppm): δ 11.74 (br, 1H), 10.24 (br, 1H), 8.59 (dd, J=4.9, 1.7Hz, 1H), 7.88-7.41(m, 3H), 6.76-6.54 (m, 2H), 5.44-5.32 (m, 1H),4.90-4.44 (m, 4H), 3.37-3.18 (m, 2H), 3.22-2.69 (m, 4H), 0.89-0.72 (m,9H), 0.13-0.11(m, 6H).

Step 6

Into a 500-mL 3-necked round-bottom flask, was placed2-[[(3R)-4-(2-[[(tert-butyldimethylsilyl)oxy]methyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(13.6 g, 27.0 mmol, 1.0 equiv) and THF (150 mL). After the reaction wascooled to 0° C., a solution of TEA.3HF (13.0 g, 80.9 mmol, 3.0 equiv)was added dropwise. The resulting solution was stirred for 5 h at 0-25°C. The pH value of the solution was adjusted to 8 with NaHCO₃ (2 mol/L).The resulting solution was extracted with ethyl acetate (200 mL×3), andthe organic layers combined and concentrated. The crude product waspurified by Flash-Prep-HPLC with the following conditions(IntelFlash-1): Column, C18 silica gel; mobile phase, MeCN=10/90increasing to MeCN=90/10; Detector, 220. This resulted in2-hydroxy-6-[[(3R)-4-[2-(hydroxymethyl)pyridine-3-carbonyl]thiomorpholin-3-yl]methoxy]benzaldehyde.LCMS (ES, m/z): [M+H]⁺: 389.1; Retention time 1.060 min.

Analytical SFC retention time: 3.641 min. Conditions for SFC were asfollows: Instrument Name: Shimadzu LC3OAD SF; Column OD-3, 100*3.0 mm, 3um; Column ID: OD3SCK-TG002; Oven Temperature: 35 C; Total Flow: 2.5000mL/min; Start Conc. of Pump B: 10.0%; BPR Pressure: 15.00 MPa.

¹H-NMR (300 MHz, DMSO-d6, ppm): δ 11.77 (br, 1H), 10.30 (br, 1H), 8.54(dd, J=4.8, 1.5 Hz, 1H), 7.76-7.36 (m, 3H), 6.75-6.52 (m, 2H), 5.45-4.07(m, 6H), 3.46-2.72 (m, 5H), 2.51-2.39(m, 1H).

Based on the product of Scheme 10B, it was determined that Compound 13,Enantiomer 1 corresponds to(R)-2-hydroxy-6-((4-(2-(2-hydroxyethyl)nicotinoyl)thiomorpholin-3-yl)methoxy)benzaldehyde.

Example 11.(S)-2-hydroxy-6-((1-(2-(2-methoxyethyl)benzoyl)piperidin-2-yl)methoxy)benzaldehyde,Compound 14

Compound 14 was synthesized according to Scheme 11.

Step 1. Synthesis of 1-bromo-2-(2-methoxyethyl)benzene

Into a 500-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen was placed 2-(2-bromophenyl)ethanol (10.0g, 49.7 mmol, 1.00 equiv) and DMF (100 mL) cooled to 0° C. by ice water,and then NaH (2.39 g, 99.5 mmol, 2.00 equiv) was added in severalportions. The resulting solution was stirred for 40 min at 0° C., andthen MeI (10.59 g, 74.610 mmol, 1.50 equiv) was added dropwise withstirring at 0° C. over 15 mins. The resulting solution was allowed towarm up to room temperature with stirring for an additional 5 hr. Thereaction was then quenched by the addition of water/ice. The resultingsolution was extracted with 3×100 mL of ethyl acetate and the organiclayers were combined and dried over anhydrous sodium sulfate andconcentrated under vacuum. The residue was purified by silica gel columnchromatography with ethyl acetate/hexane (1:3) as eluents. This resultedin 1-bromo-2-(2-methoxyethyl)benzene. LCMS (ES) [M+1]⁺ m/z: 215.

Step 2. Synthesis of ethyl 2-(2-methoxyethyl)benzoate

Into a 500-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen was placed1-bromo-2-(2-methoxyethyl)benzene (10.0 g, 46.5 mmol, 1.00 equiv) andTHF (100 mL). The mixture was cooled to -78° C., and n-butyllithium (39mL, 97.7 mmol, 2.10 equiv) was added dropwise into the solution. Theresulting solution was stirred for 40 min at −78° C., then ethylchloroformate (7.57 g, 69.757 mmol, 1.50 equiv) was added dropwise. Theresulting solution was brought to room temperature with stirring for anadditional 5 min at −78° C. and then stirred for an additional 16 hr atroom temperature. The reaction was then quenched by the addition ofwater/ice. The resulting solution was extracted with 3×100 mL of ethylacetate, and the organic layers were combined and dried over anhydroussodium sulfate. The residue was purified by silica gel columnchromatography with ethyl acetate/petroleum ether (1:5) as eluent. Thisresulted in ethyl 2-(2-methoxyethyl)benzoate. LCMS (ES) [M+1]⁺ m/z: 209.

Step 3. Synthesis of 2-(2-methoxyethyl)benzoic acid

Into a 100-mL round-bottom flask was placed ethyl2-(2-methoxyethyl)benzoate (1.20 g, 5.76 mmol, 1.00 equiv), LiOH (0.55g, 23.0 mmol, 4.00 equiv) and THF (15.0 mL), and H₂O (3.00 mL). Theresulting solution was stirred for 4 hr at 50° C. in an oil bath. Thereaction mixture was cooled with a water/ice bath. The pH of thesolution was adjusted to 5 with HCl (2M). The resulting solution wasextracted with 3×50 mL of ethyl acetate, and the organic layers werecombined and dried over anhydrous sodium sulfate and concentrated undervacuum. This resulted in 2-(2-methoxyethyl)benzoic acid. LCMS (ES)[M+1]⁺ m/z: 181.

Step 4. Synthesis of[(2S)-1-[2-(2-methoxyethyl)benzoyl]piperidin-2-yl]methanol

Into a 250-mL round-bottom flask was placed 2-(2-methoxyethyl)benzoicacid (550 mg, 3.05 mmol, 1.00 equiv), (2S)-piperidin-2-ylmethanol (421mg, 3.66 mmol, 1.20 equiv), HATU (2.32 g, 6.10 mmol, 2.00 equiv), DIEA(788 mg, 6.10 mmol, 2.00 equiv) and DCM (40.00 mL). The resultingsolution was stirred for 4 hr at room temperature. The resultingsolution was extracted with 3×30 mL of dichloromethane, and the organiclayers were combined and dried over anhydrous sodium sulfate andconcentrated under vacuum. The residue was purified by silica gel columnwith ethyl acetate/petroleum ether (2:5) as eluents. This resulted in[(2S)-1-[2-(2-methoxyethyl)benzoyl]piperidin-2-yl]methanol. LCMS (ES)[M+1]⁺ m/z: 278.

Step 5. Synthesis of(S)-2-hydroxy-6-((1-(2-(2-methoxyethyl)benzoyl)piperidin-2-yl)methoxy)benzaldehyde

Into a 100-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen was placed[(2S)-1-[2-(2-methoxyethyl)benzoyl]piperidin-2-yl]methanol (470 mg, 1.70mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (468 mg, 3.39 mmol, 2.00equiv), PPh₃ (888 mg, 3.39 mmol, 2.00 equiv) and THF (30.0 mL). Theresulting solution was stirred for 15 min at 0° C., and then DIAD (685mg, 3.39 mmol, 2.00 equiv) was added dropwise. The resulting solutionwas stirred for 15 min at 0° C. The resulting solution was warmed up toroom temperature with stirring for an additional 16 hr. The resultingsolution was extracted with 3×30 mL of ethyl acetate, and the organiclayers were combined and dried over anhydrous sodium sulfate. The crudeproduct was purified by Prep-HPLC [Column: Atlantis HILIC OBD Column,19*150 mm*5 um; mobile phase: Water(0.1% FA) and ACN (10% PhaseB up to50% in 10 min, up to 90% in 10 min)]. This resulted in(S)-2-hydroxy-6-((1-(2-(2-methoxyethyl)benzoyl)piperidin-2-yl)methoxy)benzaldehyde.LCMS (ES) [M+1]⁺ m/z: 398. ¹H NMR (300 MHz, DMSO-d6) 11.64 (br, 1H),10.29 (br, 1H), 7.50-6.98 (m, 5H), 6.81-6.65 (m, 1H), 6.53 (d, J=8.4 Hz,1H), 5.25-5.11 (m, 1H), 4.48 (d, J=11.3 Hz, 1H), 4.29 (dd, J=10.2, 6.1Hz, 1H), 3.65-3.31 (m, 2H), 3.29-2.99 (m, 2H), 3.06 (s, 3H), 2.88-2.63(m, 2H), 1.92-1.34 (m, 6H).

Example 12.(S)-3-(2-(2-((2-formyl-3-hydroxyphenoxy)methyl)piperidine-1-carbonyl)phenyl)propanenitrile,Compound 15

Compound 15 was synthesized according to Scheme 12.

Step 1. Synthesis of methyl 2-[(1E)-2-cyanoeth-1-en-1-yl]benzoate

Into a 100-mL round-bottom flask, was placed methyl 2-bromobenzoate(5.00 g, 23.251 mmol, 1.00 equiv), acrylonitrile (12.34 g, 232.508 mmol,10.00 equiv), DIEA (6.01 g, 46.502 mmol, 2.00 equiv), andbis(tributylphosphine) palladium (1.19 g, 2.325 mmol, 0.10 equiv). Theresulting solution was stirred for 16 hr at 80° C. The resulting mixturewas concentrated. The residue was applied onto a silica gel column withethyl acetate/petroleum ether (1:5) as eluents. The collected fractionswere combined and concentrated. This resulted in methyl2-[(1E)-2-cyanoeth-1-en-1-yl]benzoate. GCMS M⁺: 187.

Step 2. Synthesis of methyl 2-(2-cyanoethyl)benzoate

Into a 100-mL round-bottom flask, was placed methyl2-[(1E)-2-cyanoeth-1-en-1-yl]benzoate (2.40 g, 12.8 mmol, 1.00 equiv),methanol (50 mL), and Pd/C (0.24 g). The flask was evacuated and flushedthree times with nitrogen, followed by flushing with hydrogen. Themixture was stirred 16 h at room temperature under an atmosphere ofhydrogen. The solids were filtered out. The resulting mixture wasconcentrated. This resulted in methyl 2-(2-cyanoethyl)benzoate. LCMS(ES) [M+1]+ m/z 190.1.

Step 3. Synthesis of 2-(2-cyanoethyl)benzoic acid

Into a 100-mL round-bottom flask was placed methyl2-(2-cyanoethyl)benzoate (2.20 g, 11.627 mmol, 1.00 equiv), methanol (20mL), water (20 mL) and sodium hydroxide (0.93 g, 23.252 mmol, 2.00equiv). The resulting solution was stirred for 4 hr at 25° C. Thereaction was then quenched by the addition of 100 mL of water. The pHvalue of the solution was adjusted to 5 with HCl (1 mol/L). The solidswere collected by filtration. This resulted in 2-(2-cyanoethyl)benzoicacid. LCMS (ES) [M−1]⁻ m/z 174.1.

Step 4. Synthesis of3-[2-[(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine-1-carbonyl]phenyl]propanenitrile

Into a 100-mL round-bottom flask was placed 2-(2-cyanoethyl)benzoic acid(1.80 g, 10.275 mmol, 1.00 equiv), DCM (30.00 mL),(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine (2.36 g, 10.275mmol, 1.00 equiv), HATU (5.86 g, 15.412 mmol, 1.50 equiv) and DIEA (3.98g, 30.824 mmol, 3.00 equiv). The resulting solution was stirred for 16hr at 25° C. The resulting mixture was concentrated. The residue waspurified by silica gel column chromatography with ethylacetate/petroleum ether (1:2) as eluents. The collected fractions werecombined and concentrated. This resulted in3-[2-[2S)-2-[[(tert-butyldimethylsilyeoxy]methyl]piperidine-1-carbonyl]phenyl]propanenitrile.LCMS (ES) [M+1]⁺ m/z 387.2.

Step 5. Synthesis of3-[2-[(2S)-2-(hydroxymethyl)piperidine-1-carbonyl]phenyl]propanenitrile

Into a 100-mL round-bottom flask, was placed3-[2-[(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine-1-carbonyl]phenyl]propanenitrile(2.00 g, 5.173 mmol, 1.00 equiv), tetrahydrofuran (20 mL) and TBAF (0.27g, 1.035 mmol, 0.20 equiv). The resulting solution was stirred for 2 hrat 25° C. The resulting mixture was concentrated. The residue waspurified by silica gel column chromatography with ethylacetate/petroleum ether (1:2) as eluents. The collected fractions werecombined and concentrated. This resulted in3-[2-[(2S)-2-(hydroxymethyl)piperidine-1-carbonyl]phenyl]propanenitrile.LCMS (ES) [M+1]⁺ m/z 273.2.

Step 6. Synthesis of(S)-3-(2-(2-((2-formyl-3-hydroxyphenoxy)methyl)piperidine-1-carbonyl)phenyl)propanenitrile

Into a 50-mL round-bottom flask, was placed3-[2-[(2S)-2-(hydroxymethyl)piperidine-1-carbonyl]phenyl]propanenitrile(100.00 mg, 0.367 mmol, 1.00 equiv), tetrahydrofuran (8.00 mL),2,6-dihydroxybenzaldehyde (50.72 mg, 0.367 mmol, 1.00 equiv), PPh3(115.57 mg, 0.441 mmol, 1.20 equiv), and DIAD (89.10 mg, 0.441 mmol,1.20 equiv). The resulting solution was stirred for 16 hr at 25° C. Theresulting mixture was concentrated under vacuum. The crude reactionmixture was filtered and subjected to reverse phase preparative HPLC(Prep-C18, 20-45M, 120 g, Tianjin Bonna-Agela Technologies; gradientelution of 30% MeCN in water to 40% MeCN in water over a 10 min period,where both solvents contain 0.1% FA) to provide(S)-3-(2-(2-((2-formyl-3-hydroxyphenoxy)methyl)piperidine-1-carbonyl)phenyl)propanenitrile.LCMS (ES) [M+1]⁺ m/z 393.2. 1H NMR (300 MHz, DMSO-d6) δ 11.72 (br, 1H),10.21 (m, 1H), 7.67-7.22 (m, 4H), 7.06-6.33 (m, 2H), 5.31-5.15 (m, 1H),4.70-4.12 (m, 2H), 3.39-3.12 (m, 2H), 2.86-2.67 (m, 4H), 1.93-1.25 (m,6H).

Example 13.(S)-2-hydroxy-6-((1-(3-(2-hydroxyethyl)picolinoyl)piperidin-2-yl)methoxy)benzaldehyde,Compound 16

Compound 16 was synthesized according to Scheme 13.

Step 1. Synthesis of methyl3-[(E)-2-ethoxyethenyl]pyridine-2-carboxylate

Into a 100-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed2-[(Z)-2-ethoxyethenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.13 g,20.85 mmol, 1.50 equiv), methyl 3-bromopyridine-2-carboxylate (3.00 g,13.89 mmol, 1.00 equiv), dioxane (30.00 mL), H₂O (6.00 mL), Na2CO3 (4.42g, 41.66 mmol, 3.00 equiv), and Pd(PPh₃)₄ (1.60 g, 1.39 mmol, 0.10equiv). The resulting solution was stirred overnight at 80° C. Thereaction mixture was cooled to room temperature. The solids werefiltered out, and the filtrate was concentrated. The residue waspurified by silica gel column chromatography with THF/PE (30%) aseluent. This resulted in methyl3-[(E)-2-ethoxyethenyl]pyridine-2-carboxylate. LCMS (ES) [M+1]⁺ m/z 208.

Step 2. Synthesis of methyl 3-(2-ethoxyethyl)pyridine-2-carboxylate

Into a purged 100-mL round-bottom flask was placed methyl3-[(E)-2-ethoxyethenyl]pyridine-2-carboxylate (2.60 g, 12.55 mmol, 1.00equiv), Pd/C (500.00 mg, 4.69 mmol, 0.37 equiv), and MeOH (30.00 mL).The flask was evacuated and flushed three times with nitrogen, followedby flushing with hydrogen. The resulting solution was stirred overnightat room temperature. The solids were filtered out, and the filtrate wasconcentrated. This resulted in methyl3-(2-ethoxyethyl)pyridine-2-carboxylate. LCMS (ES) [M+1]⁺ m/z 210.

Step 3. Synthesis of 3-(2-ethoxyethyl)pyridine-2-carboxylic acid

Into a 100-mL round-bottom flask, was placed methyl3-(2-ethoxyethyl)pyridine-2-carboxylate (2.50 g, 11.95 mmol, 1.00equiv), THF (25.00 mL), H₂O (5.00 mL), and LiOH H₂O (1.00 g, 23.83 mmol,1.99 equiv). The resulting solution was stirred for 2 h at roomtemperature. The resulting mixture was concentrated and was adjusted topH 3-4 with HCl (1 mol/L). The resulting solution was extracted with3×20 mL of ethyl acetate, and the organic layers were combined and driedover anhydrous sodium sulfate and concentrated. This resulted in3-(2-ethoxyethyl)pyridine-2-carboxylic acid. LCMS (ES) [M+1]⁺ m/z 196.

Step 4. Synthesis of2-[(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine-1-carbonyl]-3-(2-ethoxyethyl)pyridine

Into a 100-mL 3-necked round-bottom flask was placed(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine (2.12 g, 9.22mmol, 1.00 equiv), 3-(2-ethoxyethyl)pyridine-2-carboxylic acid (1.80 g,9.22 mmol, 1.00 equiv), DCM (20.00 mL), Et₃N (1.87 g, 18.44 mmol, 2.00equiv), EDCI (2.12 g, 11.06 mmol, 1.20 equiv), and HOBt (1.50 g, 11.06mmol, 1.20 equiv). The resulting solution was stirred overnight at roomtemperature. The reaction was then quenched by the addition of 10 mL ofwater. The resulting solution was extracted with 3×20 mL ofdichloromethane, and the organic layers were combined and dried overanhydrous sodium sulfate and concentrated. This resulted in2-[(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine-1-carbonyl]-3-(2-ethoxyethyl)pyridine.LCMS (ES) [M+1]⁺ m/z 407.

Step 5. Synthesis of[(2S)-1-[3-(2-ethoxyethyl)pyridine-2-carbonyl]piperidin-2-yl]methanol

Into a 100-mL round-bottom flask, was placed2-[(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine-1-carbonyl]-3-(2-ethoxyethyl)pyridine(3.00 g, 7.38 mmol, 1.00 equiv), THF (20.00 mL), and TBAF/THF (14.75 mL,14.75 mmol, 2.00 equiv). The resulting solution was stirred overnight atroom temperature. The resulting mixture was concentrated. The residuewas purified by silica gel column with THF/PE (45%) as eluent. Thisresulted in[(2S)-1-[3-(2-ethoxyethyl)pyridine-2-carbonyl]piperidin-2-yl]methanol.LCMS (ES) [M+1]⁺ m/z 293.

Step 6. Synthesis of2-[[(2S)-1-[3-(2-ethoxyethyl)pyridine-2-carbonyl]piperidin-2-yl]methoxy]-6-hydroxybenzaldehyde

Into a 100-mL 3-necked round-bottom flask, was placed[(2S)-1-[3-(2-ethoxyethyl)pyridine-2-carbonyl]piperidin-2-yl]methanol(1.70 g, 5.81 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.96 g, 6.95mmol, 1.20 equiv), DCM (40.00 mL), and PPh₃ (1.83 g, 6.98 mmol, 1.20equiv). This was followed by the addition of DIAD (1.41 g, 6.98 mmol,1.20 equiv) dropwise with stirring at 0° C. The resulting solution wasstirred for 4 h at room temperature. The resulting mixture wasconcentrated. The residue was purified by silica gel column with THF/PE(30%) as eluents. This resulted in2-[[(2S)-1-[3-(2-ethoxyethyl)pyridine-2-carbonyl]piperidin-2-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z 413.

Step 7. Synthesis of(S)-2-hydroxy-6-((1-(3-(2-hydroxyethyl)picolinoyl)piperidin-2-yl)methoxy)benzaldehyde

Into a 100-mL 3-necked round-bottom flask, was placed2-[[(2S)-1-[3-(2-ethoxyethyl)pyridine-2-carbonyl]piperidin-2-yl]methoxy]-6-hydroxybenzaldehyde(500.00 mg, 1.21 mmol, 1.00 equiv) and DCM (20.00 mL). This was followedby the addition of BBr₃/DCM (12.12 mL, 12.12 mmol, 10.00 equiv) dropwisewith stirring at −78° C. The resulting solution was stirred for 1 h at0° C. The reaction was then quenched by the addition of 20 mL ofwater/ice. The resulting solution was extracted with 3×20 mL ofdichloromethane, and the organic layers were combined and dried overanhydrous sodium sulfate and concentrated. The crude product waspurified by Prep-HPLC [Column, XBridge Prep C18 OBD Column, 19 cm, 150mm, 5 um; mobile phase, Water (0.1% HCOOH) and AcCN (30% Phase B up to60% in 11 min); Detector, 254. This resulted in(S)-2-hydroxy-6-((1-(3-(2-hydroxyethyl)picolinoyl)piperidin-2-yl)methoxy)benzaldehyde.LCMS: (ES, m/z): [M+1]⁺ 385.0. ¹H-NMR (300 MHz, DMSO-d6) δ 11.81 (s,1H), 10.29 (d, J=6.6 Hz, 1H), 8.40-8.35 (m, 1H), 7.77 (dd, J=7.8, 1.6Hz, 1H), 7.57-7.44 (m, 1H), 7.36 (dd, J=7.9, 4.7 Hz, 1H), 6.73 (d, J=8.3Hz, 1H), 6.63-6.46 (m, 1H), 5.20 (s, 1H), 4.68-4.40 (m, 2H), 4.33-4.20(m, 1H), 3.67-3.56 (m, 1H), 3.60-3.52 (m, 1H), 3.22-3.00 (m, 2H),2.79-2.59 (m, 2H), 1.92-1.53 (m, 6H).

Example 14.(S)-2-hydroxy-6-((1-(2-(2-(pyrrolidin-1-yl)ethyl)benzoyl)piperidin-2-yl)methoxy)benzaldehyde,Compound 17

Compound 17 was synthesized according to Scheme 14.

Step 1. Synthesis of2-bromo-3-[[(2S)-1-[2-[(E)-2-ethoxyethenyl]benzoyl]piperidin-2-yl]methoxy]phenol

Into a 100-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen was placed a solution of[(2S)-1-[2-[(E)-2-ethoxyethenyl]benzoyl]piperidin-2-yl]methanol (5.00 g,0.017 mmol, 1.00 equiv) in THF (50 mL), 2-bromobenzene-1,3-diol (3.27 g,0.017 mmol, 1 equiv), DIAD (4.19 g, 0.021 mmol, 1.2 equiv), and PPh₃(5.44 g, 0.021 mmol, 1.2 equiv). The resulting solution was stirred for1 hr at 0° C. in an ice/salt bath, then was removed from the bath andallowed to stir overnight at room temperature. The reaction was thenquenched by the addition of water/ice. The resulting solution wasextracted with 100 mL of ethyl acetate, dried over anhydrous sodiumsulfate and concentrated. The residue was purified by silica gel columnchromatography with ethyl acetate/petroleum ether (1:4) as eluent. Thisresulted in2-bromo-3-[[(2S)-1-[2-[(E)-2-ethoxyethenyl]benzoyl]piperidin-2-yl]methoxy]phenol.LCMS (ES) [M+1]⁺ m/z 460.2.

Step 2. Synthesis of2-[2-[(2S)-2-(2-bromo-3-hydroxyphenoxymethyl)piperidine-1-carbonyl]phenyl]acetaldehyde

Into a 100-mL round-bottom flask, was placed2-bromo-3-[[(2S)-1-[2-[(E)-2-ethoxyethenyl]benzoyl]piperidin-2-yl]methoxy]phenol(3.00 g, 6.517 mmol, 1.00 equiv) and 1M HCl in EtOAc (20 mL). Theresulting solution was stirred overnight at room temperature. Theresulting mixture was concentrated under vacuum. This resulted in2-[2-[(2S)-2-(2-bromo-3-hydroxyphenoxymethyl)piperidine-1-carbonyl]phenyl]acetaldehyde.LCMS (ES) [M+1]⁺ m/z 432.2.

Step 3. Synthesis of2-bromo-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]benzoyl]piperidin-2-yl]methoxy]phenol

Into a 100-mL round-bottom flask, was placed a solution of2-[2-[(2S)-2-(2-bromo-3-hydroxyphenoxymethyl)piperidine-1-carbonyl]phenyl]acetaldehyde(2.20 g, 0.005 mmol, 1.00 equiv) in MeOH (10 mL), pyrrolidine (0.54 g,0.008 mmol, 1.5 equiv), MeOH (1 equiv), and NaBH₄ (0.48 g, 0.013 mmol,2.5 equiv). The resulting solution was stirred for 1 hr at 0° C. in anice/salt bath. The resulting solution was stirred overnight at roomtemperature. The reaction was then quenched by the addition ofwater/ice. The resulting solution was extracted with 100 mL ofdichloromethane, dried over anhydrous sodium sulfate and concentrated.The residue was purified by silica gel column chromatography withdichloromethane/methanol (1:10) as eluents. This resulted in2-bromo-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]benzoyl]piperidin-2-yl]methoxy]phenol.LCMS (ES) [M+1]⁺ m/z 487.2.

Step 4. Synthesis of2-ethenyl-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]benzoyl]piperidin-2-yl]methoxy]phenol

Into a 25-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed2-bromo-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]benzoyl]piperidin-2-yl]methoxy]phenol(600.00 mg, 1.231 mmol, 1.00 equiv) in dioxane (10 mL),2-ethenyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (189.59 mg, 1.231mmol, 1 equiv), K₂CO₃ (340.24 mg, 2.462 mmol, 2 equiv), and Pd(dppf)Cl₂(45.03 mg, 0.062 mmol, 0.05 equiv). The resulting solution was stirredovernight at 80° C. in an oil bath. The reaction was then quenched bythe addition of water. The resulting solution was extracted with 100 mLof dichloromethane, dried over anhydrous sodium sulfate, andconcentrated. The residue was purified by silica gel columnchromatography with ethyl acetate/petroleum ether (2:1) as eluent. Thisresulted in2-ethenyl-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]benzoyl]piperidin-2-yl]methoxy]phenol.LCMS (ES) [M+1]⁺ m/z 435.1.

Step 5. Synthesis of(S)-2-hydroxy-6-((1-(2-(2-(pyrrolidin-1-yl)ethyl)benzoyl)piperidin-2-yl)methoxy)benzaldehyde

Into a 10-mL round-bottom flask, was placed a solution of2-ethenyl-3-[[(2S)-1-[2-[2-(pyrrolidin-1-yl)ethyl]benzoyl]piperidin-2-yl]methoxy]phenol(120.00 mg, 0.276 mmol, 1.00 equiv) in acetone (5 mL), a solution ofNaIO₄ (118.12 mg, 0.552 mmol, 2 equiv) in H₂O (2 mL), and K₂OsO₄.2H₂O(10.17 mg, 0.028 mmol, 0.1 equiv). The resulting solution was stirredovernight at room temperature. The solids were filtered out, and thefiltrate was concentrated. The residue was purified by silica gel columnchromatography with ACN:H₂O (1:4) as eluent. This resulted in(S)-2-hydroxy-6-((1-(2-(2-(pyrrolidin-1-yl)ethyl)benzoyl)piperidin-2-yl)methoxy)benzaldehyde.LCMS (ES) [M+1]⁺ m/z 437.3. 1H NMR (300 MHz, Chloroform-d) δ 12.02 (br,1H), 10.46-10.32 (m, 1H), 7.53-7.29 (m, 3H), 7.28-7.12 (m, 2H),6.64-6.38 (m, 2H), 5.66-5.21 (m, 1H), 4.49-3.99 (m, 2H), 3.58-2.36 (m,10H), 2.16-1.16 (m, 10H).

Example 15.(S)-2-hydroxy-6-((1-(3-(2-hydroxyethyl)pyrazine-2-carbonyl)pyrrolidin-2-yl)methoxy)benzaldehyde,Compound 19

Compound 19 was synthesized according to Scheme 15.

Step 1. Synthesis of methyl 3-ethenylpyrazine-2-carboxylate

Into a 250-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed methyl 3-bromopyrazine-2-carboxylate(5.00 g, 23.04 mmol, 1.00 equiv),2-ethenyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.26 g, 27.66 mmol,1.20 equiv), dioxane (60.00 mL), H₂O (10.00 mL), K₂CO₃ (6.37 g, 46.08mmol, 2.00 equiv), and Pd(dppf)Cl₂ (1.69 g, 2.30 mmol, 0.10 equiv). Theresulting solution was stirred for 5 h at 80° C. The reaction mixturewas cooled to room temperature. The solids were filtered out. Thefiltrate was concentrated, and the resulting residue was purified bysilica gel column chromatography with THF/PE (15%) as eluent. Thisresulted in methyl 3-ethenylpyrazine-2-carboxylate. LCMS (ES) [M+1]⁺m/z: 165.

Step 2. Synthesis of 3-(2-methoxyethyl)pyrazine-2-carboxylic acid

Into a 250-mL round-bottom flask, was placed methyl3-ethenylpyrazine-2-carboxylate (3.50 g, 21.32 mmol, 1.00 equiv), MeOH(40.00 mL), and NaOMe (3.46 g, 64.05 mmol, 3.00 equiv). The resultingsolution was stirred overnight at 70° C. The resulting mixture wasconcentrated. The pH value of the solution was adjusted to 2-3 with HCl(1 mol/L). The resulting mixture was concentrated. The residue waspurified by silica gel column chromatography with MeOH/DCM (10%) aseluent. This resulted in 3-(2-methoxyethyl)pyrazine-2-carboxylic acid.LCMS (ES) [M+1]⁺ m/z: 183.

Step 3. Synthesis of[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methanol

Into a 250-mL 3-necked round-bottom flask was placed3-(2-methoxyethyl)pyrazine-2-carboxylic acid (1.50 g, 8.23 mmol, 1.00equiv), prolinol (0.83 g, 8.21 mmol, 1.00 equiv), DIEA (3.19 g, 24.70mmol, 3.00 equiv), and DMF (30.00 mL). This was followed by the additionof HATU (3.76 g, 9.88 mmol, 1.20 equiv) in portions at 0° C. Theresulting solution was stirred overnight at room temperature. The crudeproduct was purified by Prep-HPLC with the following conditions: Column,XBridge Prep C18 OBD Column, 19 cm, 150 mm, 5 um; mobile phase, Water(0.1% HCOOH) and MeCN (5% Phase B up to 20% in 10 min); Detector, 254.This resulted in[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 266.

Step 4. Synthesis of2-hydroxy-6-[[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methoxy]benzaldehyde

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methanol(1.00 g, 3.77 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.62 g, 4.49mmol, 1.19 equiv), PPh₃ (1.19 g, 4.52 mmol, 1.20 equiv), and DCM (30.00mL). This was followed by the addition of DIAD (0.91 g, 4.52 mmol, 1.20equiv) dropwise with stirring at 0° C. The resulting solution wasstirred overnight at room temperature. The resulting mixture wasconcentrated. The residue was purified by silica gel columnchromatography with EA/DCM (10%) as eluent. This resulted in2-hydroxy-6-[[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methoxy]benzaldehyde.LCMS (ES, m/z): [M+H]⁺: 386.2

Step 5. Synthesis of(S)-2-hydroxy-6-((1-(3-(2-hydroxyethyl)pyrazine-2-carbonyl)pyrrolidin-2-yl)methoxy)benzaldehyde

Into a 100-mL 3-necked round-bottom flask, was placed2-hydroxy-6-[[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methoxy]benzaldehyde(360.00 mg, 0.93 mmol, 1.00 equiv) and DCM (10.00 mL). This was followedby the addition of BBr₃/DCM (9.34 mL, 9.34 mmol, 10.00 equiv) dropwisewith stirring at -78° C. The resulting solution was stirred for 2 h at0° C. The reaction was then quenched by the addition of 20 mL ofwater/ice. The resulting solution was extracted with 3×20 mL ofdichloromethane, and the organic layers were combined and dried overanhydrous sodium sulfate and concentrated. The crude product waspurified by Prep-HPLC with the following conditions: Column, XBridgePrep C18 OBD Column, 19 cm, 150 mm, 5 um; mobile phase, Water (0.1%HCOOH) and ACN (20% Phase B up to 50% in 11 min); Detector, 254. Thisresulted in(S)-2-hydroxy-6-((1-(3-(2-hydroxyethyl)pyrazine-2-carbonyl)pyrrolidin-2-yl)methoxy)benzaldehyde.LCMS: (ES, m/z): [M+H]⁺: 372. ¹H-NMR: (300 MHz, DMSO-d6) δ 11.77 (s,1H), 10.34 (s, 1H), 8.66 (t, J=2.4 Hz, 1H), 8.51-8.46 (m, 1H), 7.57-7.40(m, 1H), 6.72 (d, J=8.3 Hz, 1H), 6.55-6.33 (m, 1H), 4.61-4.54 (m, 1H),4.34 (d, J=4.9 Hz, 2H), 3.93-3.63 (m, 3H), 3.38-3.19 (m, 2H), 3.06-2.76(m, 2H), 2.23-1.87 (m, 3H), 1.84-1. 74 (m, 1H).

Example 16.2-hydroxy-6-{[(3S)-4[2-(2-methoxyethyl)pyridine-3-carbonyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 20

Compound 20 was synthesized according to Scheme 16.

Step 1

Into a 250-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed methyl 2-chloropyridine-3-carboxylate(10.0 g, 58.28 mmol, 1.0 equiv), dioxane (100 mL),tributyl(ethenyl)stannane (37.0 g, 116.56 mmol, 2.0 equiv), andPd(dppf)Cl2 (4.26 g, 5.83 mmol, 0.1 equiv). The mixture was stirred for12 h at 80° C. in oil bath. After cooled to room temperature, thereaction mixture was concentrated under reduced pressure. The residuewas purified by silica gel column with ethyl acetate/petroleum ether(1:3) as eluents. Methyl 2-ethenylpyridine-3-carboxylate was obtained.LCMS (ES) [M+1]+ m/z: 164.

Step 2

Into a 250-mL round-bottom flask, was placed methyl2-ethenylpyridine-3-carboxylate (7.80 g, 47.90 mmol, 1.0 equiv) andMeOH(50 mL), HCl (c) (8.0 mL). The reaction solution was stirred for 12 h at90° C. in oil bath. The reaction mixture was cooled to room temperature.Methyl 2-(2-methoxyethyl)pyridine-3-carboxylate hydrochloride wasobtained and used in the next step directly without furtherpurification. LCMS (ES) [M−HCl+1]+ m/z: 196.

Step 3

Into a 250-mL round-bottom flask, was placed methyl2-(2-methoxyethyl)pyridine-3-carboxylate hydrochloride (7.0 g, 30.30mmol, 1.0 equiv), MeOH /H20 (1:2) (150 mL), and NaOH (2.40 g, 60.60mmol, 2.0 equiv). The mixture was stirred for 2 h at 50° C. in oil bath.After being cooled to room temperature, the solution was concentratedunder reduced pressure. The pH value of the residue was adjusted to 6with (6 M) HCl and purified by C18-120 g column with conditions:CH₃CN/H2O from 5% increased to 60% within 12 min2-(2-methoxyethyl)pyridine-3-carboxylic acid hydrochloride was obtained.LCMS (ES) [M−HCl+1]+ m/z: 182.

Step 4

Into a 50-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed2-(2-methoxyethyl)pyridine-3-carboxylic acid hydrochloride (1.0 g, 4.60mmol, 1.0 equiv), DMF(20 mL), DIEA (2.38 g, 18.40 mmol, 4.0 equiv), and(3R)-morpholin-3-ylmethanol hydrochloride (0.85 g, 5.51 mmol, 1.2equiv). This was followed by the addition of HATU (2.10 g, 5.51 mmol,1.2 equiv) in several batches at 0° C. The reaction solution was stirredfor 12 h at room temperature. The reaction solution was diluted with 30mL of H₂O and extracted with 3×100 mL of ethyl acetate. The combinedorganic phase was washed with 3×50 mL of brine and dried over anhydroussodium sulfate. The solution was filtered, and the filtrate wasconcentrated under reduced pressure. The residue was purified by silicagel column with ethyl acetate/petroleum ether (1:1).[(3R)-4-[2-(2-methoxyethyl)pyridine-3-carbonyl]morpholin-3-yl]methanolwas obtained. LCMS (ES) [M+1]+ m/z: 281.

Step 5

Into a 10-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed[(2S)-1-[2-(2-methoxyethyl)pyridine-3-carbonyl]pyrrolidin-2-yl]methanol(280 mg, 1.06 mmol, 1.0 equiv), THF (10 mL), 2,6-dihydroxybenzaldehyde(176 mg, 1.27 mmol, 1.2 equiv), and PPh3 (333 mg, 1.27 mmol, 1.2 equiv).The mixture was cooled to 0° C. followed by the addition of a solutionof DBAD (293 mg, 1.27 mmol, 1.2 equiv) in THF (2 mL) dropwise withstirring. After addition, the reaction solution was stirred for 12 h atroom temperature. The resulting mixture was concentrated in vacuum toremove the solvent, and the crude product was purified by Prep-HPLC withthe following conditions (IntelFlash-1): Column: Ascentis Express C18,50*3.0 mm, 2.7 um, Mobile Phase A: Water/0.05% FA, Mobile Phase B:CH₃CN, Flow rate: 1.5 mL/min, Gradient: 5% B to 100% B within 1.2 min,hold 0.6 min. This resulted in isolation of2-hydroxy-6-[[(2S)-1-[2-(2-methoxyethyl)pyridine-3-carbonyl]pyrrolidin-2-yl]methoxy]benzaldehyde.LCMS: (ES, m/z): [M+H]⁺: 401.2. ¹H-NMR: (300 MHz, DMSO-d6, ppm): δ 11.76(s, 1H), 10.12 (s, 1H), 8.57 (dd, J=4.8, 1.8 Hz, 1H), 7.73-7.31 (m, 3H),6.75 (d, J=8.4 Hz, 1H), 6.56 (d, J=8.1 Hz, 1H), 5.05-4.89 (m, 1H),4.45-4.33 (m, 2H), 4.11-3.92 (m, 1H), 3.73-3.35 (m, 6H), 3.20-2.79 (m,6H).

Example 17.2-hydroxy-6-{[(3S)-4-[3-(2-hydroxyethyl)pyrazine-2-carbonyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 21

Compound 21 was synthesized according to Scheme 17.

Into a 100-mL 3-necked round-bottom flask, was placed2-hydroxy-6-[[(3S)-4-[3-(2-methoxyethyl)pyrazine-2-carbonyl]morpholin-3-yl]methoxy]benzaldehyde(500.00 mg, 1.25 mmol, 1.00 equiv), which was prepared as described inScheme 23, and DCM (10.00 mL). This was followed by the addition ofBBr₃/DCM (12.46 mL, 12.46 mmol, 10.00 equiv) dropwise with stirring at−78° C. The resulting solution was stirred for 2 h at 0° C. Theresulting solution was extracted with 3×20 mL of dichloromethane, andthe organic layers were combined, dried over anhydrous sodium sulfate,and concentrated. The crude product was purified by Prep-HPLC with thefollowing conditions: Column, XBridge Prep C18 OBD Column, 19 cm, 150mm, 5 um; mobile phase, Water (0.1% HCOOH) and CAN (20% Phase B up to50% in 11 min); Detector, 254. This resulted in2-hydroxy-6-[[(3S)-4-[3-(2-hydroxyethyl)pyrazine-2-carbonyl]morpholin-3-yl]methoxy]benzaldehyde.LCMS: (ES, m/z): [M+H]⁺: 388. ¹H-NMR: (300 MHz, DMSO-d₆) δ 11.77 (d,J=11.9 Hz, 1H), 10.26 (d, J=13.1 Hz, 1H), 8.68-8.66 (m, 1H), 8.49-8.45(m, 1H), 7.57 (d, J=8.4 Hz, 1H), 7.56-7.43 (m, 1H), 6.75-6.49 (m, 2H),4.99-4.93 (m, 1H), 4.76-4.63 (m, 1H), 4.55-4.32 (m, 2H), 4.14-3.89 (m,1H), 3.86-3.68 (m, 2H), 3.73-3.61 (m, 1H), 3.66-3.46 (m, 1H), 3.51-3.30(m, 2H), 3.17-2.80 (m, 3H).

Example 18.2-hydroxy-6-{[(3S)-4-[2-(2-hydroxyethyl)benzoyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 22

Compound 22 was synthesized according to Scheme 18.

Step 1

Into a 250-mL round-bottom flask, was placed methyl 2-bromobenzoate(5.00 g, 23.251 mmol, 1.00 equiv), dioxane (60.00 mL), water (10 mL),2-[(E)-2-ethoxyethenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (6.91 g,34.876 mmol, 1.50 equiv), sodium methaneperoxoate sodium (4.98 g, 46.502mmol, 2.00 equiv), and tetrakis(triphenylphosphine)palladium(0) (2.69 g,2.325 mmol, 0.10 equiv). The resulting solution was stirred for 16 hr at80° C. The resulting mixture was concentrated. The residue was purifiedby silica gel column chromatography with ethyl acetate/petroleum ether(1:3) as eluents. The collected fractions were combined andconcentrated. This resulted in methyl 2-[(E)-2-ethoxyethenyl]benzoate.LCMS (ES) [M+1]⁺ m/z 207.1.

Step 2

Into a 100-mL round-bottom flask, was placed methyl2-[(E)-2-ethoxyethenyl]benzoate (2.40 g, 11.637 mmol, 1.00 equiv),methanol (30.00 mL), and Pd/C (240.00 mg). The flask was evacuated andflushed three times with nitrogen, followed by flushing with hydrogen.The mixture was stirred 2 h at room temperature under an atmosphere ofhydrogen. The solids were filtered out. The resulting filtrate wasconcentrated to give methyl 2-(2-ethoxyethyl)benzoate. LCMS (ES) [M+1]⁺m/z 209.1.

Step 3

Into a 50-mL round-bottom flask, was placed methyl2-(2-ethoxyethyl)benzoate (2.00 g, 9.604 mmol, 1.00 equiv), methanol(10.00 mL), water (10.00 mL), caustic soda (0.77 g, 19.251 mmol, 2.00equiv). The resulting solution was stirred for 4 hr at 25° C. Theresulting solution was diluted with 50 mL of water. The pH value of thesolution was adjusted to 5 with HCl (1 mol/L). The solids were collectedby filtration to give 2-(2-ethoxyethyl)benzoic acid. LCMS (ES) [M+1]⁺m/z 195.1.

Step 4

Into a 100-mL round-bottom flask, was placed 2-(2-ethoxyethyl)benzoicacid (1.50 g, 7.723 mmol, 1.00 equiv), DCM (30.00 mL),(3R)-morpholin-3-ylmethanol (0.90 g, 7.723 mmol, 1.00 equiv), HATU (4.40g, 11.584 mmol, 1.50 equiv), and DIEA (2.99 g, 23.168 mmol, 3.00 equiv).The resulting solution was stirred for 2 hr at 25° C. The resultingmixture was concentrated. The residue was purified by silica gel columnwith ethyl acetate/petroleum ether (1:1) as eluents. The collectedfractions were combined and concentrated to give[(3R)-4-[2-(2-ethoxyethyl)benzoyl]morpholin-3-yl]methanol. LCMS (ES)[M+1]⁺ m/z 294.2.

Step 5

Into a 520-mL round-bottom flask, was placed[(3R)-4-[2-(2-ethoxyethyl)benzoyl]morpholin-3-yl]methanol (600.00 mg,2.045 mmol, 1.00 equiv), tetrahydrofuran (20 mL),2,6-dihydroxybenzaldehyde (282.49 mg, 2.045 mmol, 1.00 equiv),triphenylphosphine (643.74 mg, 2.454 mmol, 1.20 equiv), and DIAD (496.28mg, 2.454 mmol, 1.20 equiv). The resulting solution was stirred for 16hr at 25° C. The resulting mixture was concentrated. The residue waspurified by silica gel column with ethyl acetate/petroleum ether (1:2)as eluents. The collected fractions were combined and concentrated. Thisresulted in2-[[(3S)-4-[2-(2-ethoxyethyl)benzoyl]morpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z 414.2.

Step 6

Into a 50-mL round-bottom flask, was placed2-[[(3S)-4-[2-(2-ethoxyethyl)benzoyl]morpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(200 mg, 0.48 mmol, 1.0 eq), DCM(20 mL). Then, boron tribromide (2.4 mL,2.4 mmol, 5.0 eq, 1M) was added dropwise at −78° C. The resultingsolution was stirred for 3 hr at 0° C. The reaction was then quenched bythe addition of 10 mL of water. The resulting solution was extractedwith 2×20 mL of dichloromethane and concentrated. The crude reactionmixture was filtered and subjected to reverse phase preparative HPLC(Prep-C18, 20-45M, 120 g, Tianjin Bonna-Agela Technologies; gradientelution of 25% MeCN in water to 35% MeCN in water over a 10 min period,where both solvents contain 0.1% FA) to provide2-hydroxy-6-{[(3S)-4-[2-(2-hydroxyethyl)benzoyl]morpholin-3-yl]methoxy}benzaldehyde.LCMS (ES) [M+1]⁺ m/z 386.1. ¹H NMR (300 MHz, DMSO-d6) δ 11.76 (br, 1H),10.29 (s, 1H), 7.62-7.50 (m, 1H), 7.48-6.95 (m, 4H), 6.88-6.48 (m, 2H),5.00-4.20 (m, 4H), 4.17-3.41 (m, 7H), 3.23-29.5(m, 1H),2.94-2.57 (m,2H).

Example 19.2-hydroxy-6-{[(3S)-4-[2-(hydroxymethyl)benzoyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 23

Compound 23 was synthesized according to Scheme 19.

Step 1

Into a 500-mL round-bottom flask, was placed phthalide (11.00 g, 82.008mmol, 1.00 equiv), H₂O (200.00 mL, 11101.675 mmol, 135.37 equiv), andNaOH (4.92 g, 123.009 mmol, 1.50 equiv). The resulting solution wasstirred for overnight at 100° C. in an oil bath. The reaction mixturewas cooled to 0° C. with a water/ice bath. The pH value of the solutionwas adjusted to 5 with HCl (6 mol/L). The solids were collected byfiltration. The solid was dried in an oven. This resulted in2-hydroxymethylbenzoic acid. LCMS (ES) [M−1]⁻ m/z 151.1.

Step 2

Into a 250-mL round-bottom flask, was placed 2-hydroxymethylbenzoic acid(5.00 g, 32.863 mmol, 1.00 equiv), DCM (100.00 mL), and imidazole (4.47g, 65.725 mmol, 2.00 equiv). This was followed by the addition ofTBDPSCl (10.84 g, 39.435 mmol, 1.20 equiv) in several batches at 0° C.in 5 min. The resulting solution was stirred for 2 h at roomtemperature. The resulting solution was diluted with 60 mL of water. Theresulting solution was extracted with 3×100 mL of dichloromethane, andthe organic layer was washed with 1×60 mL of brine, dried over anhydroussodium sulfate, and concentrated. The residue was purified by silica gelcolumn chromatography with dichloromethane/ethyl acetate (10% EA-20%EA). This resulted in 2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoicacid. LCMS (ES) [M+1]⁺ m/z 391.2.

Step 3

Into a 250-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoic acid (2.00 g, 5.121mmol, 1.00 equiv), DCM (120 mL), and oxalyl chloride (1.30 g, 10.242mmol, 2.00 equiv). The resulting solution was stirred for 4 h at roomtemperature. The resulting mixture was concentrated under vacuum. Intoanother 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed (3R)-morpholin-3-ylmethanolhydrochloride (0.94 g, 6.145 mmol, 1.20 equiv) and TEA (1.55 g, 15.318mmol, 2.99 equiv). This was followed by the addition of a solution of2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl chloride (2.00 g, 4.890mmol, 1.00 equiv) in DCM (30 mL) dropwise with stirring at 0° C. in 30min. The resulting solution was stirred for 2 h at room temperature. Theresulting solution was diluted with 200 mL of DCM. The resulting mixturewas washed with 1×100 mL of 1 M HCl. The mixture was dried overanhydrous sodium sulfate and concentrated. The residue was purified bysilica gel column chromatography with ethyl acetate/petroleum ether(50%EA). This resulted in[(3R)-4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)morpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z 490.3.

Step 4

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed[(3R)-4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyflmorpholin-3-yl]methanol(1.00 g, 2.042 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.56 g,4.084 mmol, 2.00 equiv), PPh₃ (1.07 g, 4.084 mmol, 2.00 equiv), and THF(60.00 mL). The resulting solution was stirred for 15 min at 0° C. Thiswas followed by the addition of DIAD (825.87 mg, 4.084 mmol, 2.00 equiv)dropwise with stirring at 0° C. in 5 min. The resulting solution wasstirred for 5 h at room temperature. The resulting solution was dilutedwith 30 mL of water. The resulting solution was extracted with 3×60 mLof dichloromethane; the organic layer was dried over anhydrous sodiumsulfate and concentrated. The residue was purified by silica gel columnchromatography with PE/THF (10% THF). This resulted in2-[[(3S)-4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)morpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z 610.3.

Step 5

Into a 100-mL round-bottom flask, was placed2-[[(3S)-4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)morpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(0.80 g, 1.312 mmol, 1.00 equiv), THF (30.00 mL), and TBAF (1.32 mL, 2.0equiv, 2 M). The resulting solution was stirred for 2 hr at roomtemperature. The resulting solution was diluted with 10 mL of water. Theresulting solution was extracted with 3×60 mL of dichloromethane, andthe organic layer was dried over anhydrous sodium sulfate andconcentrated. The residue was purified by silica gel column with PE/THF(55% THF) as eluents. The crude product was further purified byFlash-Prep-HPLC (Prep-C18, 20-45M, 120 g, Tianjin Bonna-AgelaTechnologies; gradient elution of 35% MeCN in water to 60% MeCN in waterover a 10 min period, where both solvents contain 0.1% FA). Thisresulted in2-hydroxy-6-[[(3S)-4-[2-(hydroxymethyl)benzoyl]morpholin-3-yl]methoxy]benzaldehyde.LCMS (ES) [M+1]⁺ m/z 372.1. ¹H-NMR (300 MHz, DMSO-d₆ ppm) δ 11.78 (s,1H), 10.21 (s, 1H), 7.70-7.21 (m, 5H), 6.77 (d, J=8.2 Hz, 1H), 6.56 (d,J=8.4 Hz, 1H), 5.32-5.15(m, 1H), 5.03-4.21 (m, 5H), 4.18-3.84 (m, 2H),3.78-3.55 (m, 2H), 3.42-3.36 (m, 1H), 3.11-2.98 (m, 1H).

Example 20.2-hydroxy-6-{[(2S)-1-[2-(2-methoxyethyl)pyridine-3-carbonyl]pyrrolidin-2-yl]methoxy}benzaldehyde,Compound 24

Compound 24 was synthesized according to Scheme 20.

Step 1

Into a 50-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed2-(2-methoxyethyl)pyridine-3-carboxylic acid (1.0 g, 5.52 mmol, 1.0equiv), DMF (20 mL), prolinol (670 mg, 6.62 mmol, 1.2 equiv), and DIEA(2.85 g, 22.08 mmol, 4.0 equiv). This was followed by the addition ofHATU (2.52 g, 6.62 mmol, 1.2 equiv) in several batches at 0° C. Afteraddition, the mixture was stirred for 12 h at room temperature. Thereaction solution was diluted with 30 mL of H₂O and extracted with 3×100mL of ethyl acetate. The combined organic phase was washed with 3*50 mLof brine and dried over anhydrous sodium sulfate. The solution wasfiltered, and the filtrate was concentrated under reduced pressure. Theresidue was purified by silica gel column with ethyl acetate.[(2S)-1-[2-(2-methoxyethyl)pyridine-3-carbonyl]pyrrolidin-2-yl]methanolwas obtained. LCMS (ES) [M+1]⁺ m/z: 265.

Step 2

Into a 50-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed[(2S)-1-[2-(2-methoxyethyl)pyridine-3-carbonyl]pyrrolidin-2-yl]methanol(380 mg, 1.44 mmol, 1.0 equiv), THF (20 mL), 2,6-dihydroxybenzaldehyde(199 mg, 1.44 mmol, 1.0 equiv), and PPh₃ (377 mg, 1.44 mmol, 1.0 equiv).The mixture was cooled to 0° C. and stirred for 15 min. This wasfollowed by the addition of a solution of DBAD (331 mg, 1.44 mmol, 1.0equiv) in THF (2 mL) dropwise with stirring. After addition, thereaction solution was stirred for 12 h at room temperature. The solutionwas then concentrated under reduced pressure to remove the solvent. Theresidue was purified by Flash-Prep-HPLC with the following conditions(IntelFlash-1): Column: Ascentis Express C18, 50*3.0 mm, 2.7 um, MobilePhase A: Water/0.05% FA, Mobile Phase B: CH₃CN, Flow rate: 1.5 mL/min,Gradient: 5% B to 100% B within 1.2 min, hold 0.6 min.2-hydroxy-6-{[(2S)-1-[2-(2-methoxyethyl)pyridine-3-carbonyl]pyrrolidin-2-yl]methoxy}benzaldehydewas obtained. LCMS: (ES, m/z): [M+H]⁺: 385. ¹H-NMR: (300 MHz, DMSO-d₆,ppm): δ 11.78 (s, 1H), 10.33 (s, 1H), 8.55 (dd, J=1.5, 4.8 Hz, 1H), 7.64(dd, J=7.5, 1.8 Hz, 1H), 7.57-7.52 (m, 1H), 7.32-7.28 (m, 1H), 6.70 (d,J=8.4 Hz, 1H), 6.53 (d, J=8.4 Hz, 1H), 4.57-4.53 (m, 1H), 4.44-4.39 (m,1H), 4.31-4.26 (m, 1H), 3.79-3.52 (m, 2H), 3.31-3.11 (m, 2H), 3.11 (s,3H), 3.04-2.79 (m, 2H), 2.24-1.89 (m, 3H), 1.84-1.76 (m, 1H).

Example 21.2-hydroxy-6-{[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methoxy}benzaldehyde,Compound 25

Compound 25 was synthesized according to Scheme 21.

Step 1

Into a 250-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed methyl 3-bromopyrazine-2-carboxylate(5.00 g, 23.04 mmol, 1.00 equiv),2-ethenyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.26 g, 27.66 mmol,1.20 equiv), dioxane (60.00 mL), H₂O (10.00 mL), K2CO3 (6.37 g, 46.08mmol, 2.00 equiv), and Pd(dppf)Cl₂ (1.69 g, 2.30 mmol, 0.10 equiv). Theresulting solution was stirred for 5 h at 80° C. The reaction mixturewas cooled to room temperature. The solids were filtered out. Theresulting mixture was concentrated. The residue was purified by silicagel column chromatography with THF/PE (15%) as eluents. This resulted inmethyl 3-ethenylpyrazine-2-carboxylate. LCMS (ES) [M+1]⁺ m/z: 165.

Step 2

Into a 250-mL round-bottom flask, was placed methyl3-ethenylpyrazine-2-carboxylate (3.50 g, 21.32 mmol, 1.00 equiv), MeOH(40.00 mL), and NaOMe (3.46 g, 64.05 mmol, 3.00 equiv). The resultingsolution was stirred for overnight at 70° C. The resulting mixture wasconcentrated. The pH value of the solution was adjusted to 2-3 with HCl(1 mol/L). The resulting mixture was concentrated. The residue waspurified by silica gel column with MeOH/DCM (10%) as eluents. Thisresulted in 3-(2-methoxyethyl)pyrazine-2-carboxylic acid. LCMS (ES)[M+1]⁺ m/z: 183.

Step 3

Into a 250-mL 3-necked round-bottom flask, was placed3-(2-methoxyethyl)pyrazine-2-carboxylic acid (1.50 g, 8.23 mmol, 1.00equiv), prolinol (0.83 g, 8.21 mmol, 1.00 equiv), DIEA (3.19 g, 24.70mmol, 3.00 equiv), and DMF (30.00 mL). This was followed by the additionof HATU (3.76 g, 9.88 mmol, 1.20 equiv) in portions at 0° C. Theresulting solution was stirred for overnight at room temperature. Thecrude product was purified by Prep-HPLC with the following conditions:Column, XBridge Prep C18 OBD Column, 19 cm, 150 mm, 5 um; mobile phase,Water (0.1% HCOOH) and MeCN (5% Phase B up to 20% in 10 min); Detector,254. This resulted in[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 266.

Step 4

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methanol(1.00 g, 3.77 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.62 g, 4.49mmol, 1.19 equiv), PPh₃ (1.19 g, 4.52 mmol, 1.20 equiv), and DCM (30.00mL). This was followed by the addition of DIAD (0.91 g, 4.52 mmol, 1.20equiv) dropwise with stirring at 0° C. The resulting solution wasstirred for overnight at room temperature. The resulting mixture wasconcentrated. The residue was applied onto a silica gel column withEA/DCM (10%). This resulted in2-hydroxy-6-[[(2S)-1-[3-(2-methoxyethyl)pyrazine-2-carbonyl]pyrrolidin-2-yl]methoxy]benzaldehyde.LCMS: (ES, m/z): [M+H]⁺: 386.2. ¹H-NMR: (300 MHz, DMSO-d₆) δδ 11.77 (s,1H), 10.34 (s, 1H), 8.67 (d, J=2.6 Hz, 1H), 8.51 (d, J=2.5 Hz, 1H),7.57-7.40 (m, 1H), 6.72-6.33 (m, 2H), 4.58-4.24 (m, 3H), 3.83-3.43 (m,2H), 3.39-3.19 (m, 2H), 3.13 (s, 3H), 3.10-2.86 (m, 2H), 2.23-1.73 (m,4H).

Example 22.2-hydroxy-6-{[(2S)-1-[2-(hydroxymethyl)benzoyl]pyrrolidin-2-yl]methoxy}benzaldehyde,Compound 26

Compound 26 was synthesized according to Scheme 22.

Step 1

Into a 100-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoic acid (2.00 g, 5.121mmol, 1.00 equiv), DCM (60.00 mL), and DMF (0.05 mL, 0.646 mmol, 0.13equiv). This was followed by the addition of oxalyl chloride (1.30 g,10.243 mmol, 2.00 equiv). The resulting solution was stirred for 1overnight at room temperature. The resulting mixture was concentrated.This resulted in 2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoylchloride.

Step 2

Into a 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed prolinol (0.59 g, 5.868 mmol,1.2 equiv), TEA (1.48 g, 14.670 mmol, 3 equiv), and DCM (100.00 mL).This was followed by the addition of a solution of2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl chloride (2.00 g, 4.890mmol, 1.00 equiv) in DCM (30 mL) dropwise with stirring at 0° C. in 30min The resulting solution was stirred for 2 h at room temperature. Theresulting solution was diluted with 100 mL of DCM. The resulting mixturewas washed with 1×70 mL of 1 M HCl. The mixture was dried over anhydroussodium sulfate and concentrated. The residue was purified by silica gelcolumn chromatography with ethyl acetate/petroleum ether (55% EA) aseluents. This resulted in[(2S)-1-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)pyrrolidin-2-yl]methanol.LCMS (ES) [M+1]⁺ m/z 474.2.

Step 3

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed[(2S)-1-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)pyrrolidin-2-yl]methanol(1.00 g, 2.111 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.58 g,4.222 mmol, 2.00 equiv), PPh₃ (1.11 g, 4.222 mmol, 2.00 equiv), and THF(60 mL). The resulting solution was stirred for 15 min at 0° C. This wasfollowed by the addition of DIAD (0.85 g, 4.222 mmol, 2.00 equiv)dropwise with stirring at 0° C. in 5 min. The resulting solution wasstirred for 5 h at room temperature. The resulting solution was dilutedwith 30 mL of water. The resulting solution was extracted with 3×100 mLof dichloromethane; the organic layer was dried over anhydrous sodiumsulfate and concentrated. The residue was purified by silica gel columnchromatography with PE/THF (12% THF) as eluents. This resulted in2-[[(2S)-1-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)pyrrolidin-2-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z 594.3.

Step 4

Into a 100-mL round-bottom flask, was placed2-[[(2S)-1-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)pyrrolidin-2-yl]methoxy]-6-hydroxybenzaldehyde(1.10 g, 1.852 mmol, 1.00 equiv), THF (30.00 mL), and TBAF (1.9 mL, 2M). The resulting solution was stirred for 2 h at room temperature. Theresulting solution was diluted with 10 mL of water. The resultingsolution was extracted with 3×60 mL of dichloromethane; the organiclayer was dried over anhydrous sodium sulfate and concentrated. Theresidue was applied onto a silica gel column with PE/THF (52% THF). Thecrude product was purified by Flash-Prep-HPLC (Prep-C18, 20-45M, 120 g,Tianjin Bonna-Agela Technologies; gradient elution of 35% MeCN in waterto 60% MeCN in water over a 10 min period, where both solvents contain0.1% FA). This resulted in2-hydroxy-6-[[(2S)-1-[2-(hydroxymethyl)benzoyl]pyrrolidin-2-yl]methoxy]benzaldehyde.LCMS (ES) [M+1]⁺ m/z 356.1. ¹H-NMR (300 MHz, DMSO-d₆,ppm) δ 11.72 (s,1H), 10.22 (s, 1H), 7.80-7.13 (m, 5H), 6.78-6.41 (m, 2H), 5.22-5.10 (m,1H), 4.58-4.28 (m, 4H), 4.07-3.46 (m, 1H), 3.38-3.09 (m, 6.8 Hz, 2H),2.18-1.70 (m, 4H).

Example 23.2-hydroxy-6-{[(3S)-4-[3-(2-methoxyethyl)pyrazine-2-carbonyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 27

Compound 27 was synthesized according to Scheme 23.

Step 1

Into a 100-mL 3-necked round-bottom flask, was placed3-(2-methoxyethyl)pyrazine-2-carboxylic acid (2.00 g, 10.98 mmol, 1.00equiv), (3S)-3-[[(tert-butyldimethylsilyl)oxy]methyl]morpholine (2.54 g,10.98 mmol, 1.00 equiv), Et₃N (2.22 g, 21.94 mmol, 2.00 equiv), DCM (30mL), and EDCI (2.53 g, 13.17 mmol, 1.20 equiv). This was followed by theaddition of HOBt (1.78 g, 13.17 mmol, 1.20 equiv) in portions at 0° C.The resulting solution was stirred for overnight at room temperature.The reaction was then quenched by the addition of 30 mL of water. Theresulting solution was extracted with 3×30 mL of dichloromethane, andthe organic layers were combined, dried over anhydrous sodium sulfate,and concentrated. The residue was purified by silica gel column withTHF/PE (40%) as eluents. This resulted in(3S)-3-[[(tert-butyldimethylsilyl)oxy]methyl]-4-[3-(2-methoxyethyl)pyrazine-2-carbonyl]morpholine.LCMS (ES) [M+1]⁺ m/z: 396.

Step 2

Into a 100-mL round-bottom flask, was placed(3S)-3-[[(tert-butyldimethylsilyl)oxy]methyl]-4-[3-(2-methoxyethyl)pyrazine-2-carbonyl]morpholine(4 g, 10.11 mmol, 1.00 equiv) and EA (20.00 mL). To the above HCl_((g))in EA (10.11 mL, 20.22 mmol, 2.00 equiv) was introduced in dropwise withstirring at 0° C. The resulting solution was stirred for 2 h at roomtemperature. The resulting mixture was concentrated. The pH value of thesolution was adjusted to 7-8 with saturated NaHCO₃. The resultingsolution was extracted with 5×30 mL of dichloromethane, and the organiclayers were combined, dried over anhydrous sodium sulfate, andconcentrated. The residue was purified by silica gel column withdichloromethane/methanol (100/3) as eluents. This resulted in[(3R)-4-[3-(2-methoxyethyl)pyrazine-2-carbonyl]morpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 282.

Step 3

Into a 100-mL 3-necked round-bottom flask, was placed[(3R)-4-[3-(2-methoxyethyl)pyrazine-2-carbonyl]morpholin-3-yl]methanol(400.00 mg, 1.42 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (235.68mg, 1.71 mmol, 1.20 equiv), DCM (10.00 mL), and PPh₃ (447.54 mg, 1.71mmol, 1.20 equiv). This was followed by the addition of DIAD (345.03 mg,1.71 mmol, 1.20 equiv) dropwise with stirring at 0° C. The resultingsolution was stirred for overnight at room temperature. The resultingmixture was concentrated. The crude product was purified by Prep-HPLCwith the following conditions: Column, XBridge Prep C18 OBD Column, 19cm, 150 mm, 5 um; mobile phase, Water (0.1% HCOOH) and CAN (30% Phase Bup to 50% in 11 min); Detector, 254. This resulted in2-hydroxy-6-{[(3S)-4-[3-(2-methoxyethyl)pyrazine-2-carbonyl]morpholin-3-yl]methoxy}benzaldehyde.LCMS: (ES, m/z): [M+H]⁺: 402. ¹H-NMR: (300 MHz, DMSO-d₆) δ 11.79 (s,1H), 10.31-10.20 (m, 1H), 8.69-8.66 (m, 1H), 8.52-8.47 (m, 1H),7.58-7.45 (m, 1H), 6.79-6.70 (m, 1H), 6.64-6.48 (m, 1H), 5.00-4.94 (m,1H), 4.52-4.31 (m, 2H), 4.14-3.92 (m, 1H), 3.81-3.23 (m, 6H), 3.14 (s,3H), 3.09-2.88 (m, 3H).

Example 24. 3-{3-[(3S)-3-[(2-formyl-3-hydroxyphenoxy)methyl]morpholinecarbonyl]pyridin-2-yl}propanenitrile, Compound 28

Compound 28 was synthesized according to Scheme 24.

Step 1

Into a 40-mL vial was placed methyl 2-chloropyridine-3-carboxylate (2.00g, 11.66 mmol, 1.00 equiv), DMF (15.00 mL), NaOAc (1.91 g, 23.31 mmol,2.00 equiv), PPh₃ (1.22 g, 4.66 mmol, 0.40 equiv), Pd(OAc)₂ (0.26 g,1.17 mmol, 0.10 equiv), and acrylonitrile (3.09 g, 58.28 mmol, 5.00equiv). The resulting solution was stirred for overnight at 130° C. inan oil bath. The reaction was then quenched by water (20 mL) andextracted with EA (40 mL). The organic layer was washed by water (40 mL)two times, dried over anhydrous sodium sulfate and concentrated undervacuum. The residue was purified by silica gel column chromatographywith ethyl acetate/petroleum ether (0-9.9%) as eluents. This resulted inmethyl 2-[(1E)-2-cyanoeth-1-en-1-yl]pyridine-3-carboxylate. LCMS: (ES,m/z): [M+H]⁺ 189.1.

Step 2

Into Into a 50-mL round-bottom flask, was placed methyl(E)-2-(2-cyanovinyl)nicotinate (1.40 g, 7.44 mmol, 1.00 equiv), CH₃OH(20 mL), and Pd/C (140.0 mg, 10%). To the above, H₂ was introduced. Theresulting solution was stirred for 1 hr at room temperature. The solidswere filtered out, and the mixture was concentrated and purified bysilica gel column chromatography with ethyl acetate/petroleum ether(0-15%) as eluents. This resulted in methyl 2-(2-cyanoethyl)nicotinate.LCMS: (ES, m/z): [M+H]⁺: 190.1.

Step 3

Into a 50-mL round-bottom flask, was placed methyl2-(2-cyanoethyl)nicotinate (1.00 g, 5.26 mmol, 1.00 equiv) and THF (12mL). Then, a solution of LiOH (0.44 g, 10.49 mmol, 1.99 equiv) in H₂O(6mL) was added. The resulting solution was stirred for 1 hr at roomtemperature and concentrated. The pH value of the solution was adjustedto 5-6 with HCl (2 mol/L). The residue was purified with the followingconditions: column, C18; mobile phase, water (0.05% FA) and CH₃CN (5% upto 80% in 8 min); Detector, 220 & 254 nm; Flow rate, 40 mL/min Thisresulted in 2-(2-cyanoeth-yl)nicotinic acid. LCMS (ES, m/z): [M+H]⁺:177.1.

Step 4

Into a 50-mL round-bottom flask, was placed2-(2-cyanoethyl)pyridine-3-carboxylic acid (300.0 mg, 1.70 mmol, 1.00equiv), HATU (777.0 mg, 2.04 mmol, 1.20 equiv), DMF (10 mL), DIEA (550.2mg, 4.26 mmol, 2.50 equiv), and(3S)-3-[[(tert-butyldimethylsilyl)oxy]methyl]morpholine cyclohexane(430.0 mg, 1.86 mmol, 1.09 equiv). The resulting solution was stirredfor 2 hr at room temperature. The reaction was then quenched by theaddition of water. The resulting solution was extracted with 3×20 mL ofethyl acetate, dried over anhydrous sodium sulfate, and concentrated.The residue was purified by silica gel column chromatography with ethylacetate/petroleum ether (0-50%) as eluents. This resulted in(S)-3-(3-(3-(((tert-butyldimethylsilyl)oxy)methyl)morpholine-4-carbonyl)pyridin-2-yl)-propanenitrile.LCMS (ES, m/z): [M+H]⁺: 390.2.

Step 5

Into a 50-mL round-bottom flask, was placed(S)-3-(3-(3-(((tert-butyldimethylsilyl)oxy)methyl)-morpholine-4-carbonyl)pyridin-2-yl)-propanenitrile(0.63 g, 1.62 mmol, 1.00 equiv), THF (10 mL, 123.43 mmol, 76.3 equiv),and TBAF(1.0 M) (2.43 mL, 2.43 mmol, 1.50 equiv). The resulting solutionwas stirred for 2 hr at room temperature. The resulting mixture wasconcentrated and purified by silica gel column chromatography withdichloromethane/methanol (94.6:5.4) as eluents. This resulted in(R)-3-(3-(3-(hydroxymethyl)morpholine-4-carbonyl)pyridin-2-yl)propanenitrile.LCMS (ES, m/z): [M+H]⁺: 276.1.

Step 6

Into a 40-mL vial purged and maintained with an inert atmosphere ofnitrogen, was placed(R)-3-(3-(3-(hydroxymethyl)morpholine-4-carbonyl)pyridin-2-yl)propanenitrile(0.24 g, 0.87 mmol, 1.00 equiv), THF (10 mL), PPh₃ (274.4 mg, 1.05 mmol,1.20 equiv), and 2,6-dihydroxybenzaldehyde (156.5 mg, 1.13 mmol, 1.30equiv). Then, DBAD (240.9 mg, 1.05 mmol, 1.20 equiv) was dropwise at 0°C. After 20 min, the resulting solution was stirred at 40° C. forovernight. The resulting mixture was concentrated. The residue waspurified by silica gel column chromatography with ethylacetate/petroleum ether (0-80%) as eluents. The crude product waspurified by Prep-HPLC with the following conditions: Column, Kinetex EVOC18, 21.2*150 mm, 5 um; Mobile phase; water(0.1% FA) and CH₃CN(35% up to75% in 14 min). Detector; 220 nm. Flow rate, 20 mL/min This resulted in3-{3-[(3S)-3-[(2-formyl-3-hydroxyphenoxy)methyl]morpholine-4-carbonyl]pyridin-2-yl}propanenitrile.LCMS: (ES, m/z): [M+H]⁺: 396.2. ¹H-NM: (300 MHz, DMSO-d6, ppm): δ 11.72(s, 1H), 10.17 (s, 1H), 8.62 (dd, J=4.9, 1.7 Hz, 1H), 7.78-7.36 (m, 3H),6.76 (d, J=8.3 Hz, 1H), 6.55 (d, J=8.2 Hz, 1H), 4.94-4.89 (m, 1H),4.49-4.27 (m, 2H), 4.10-3.45 (m, 5H), 3.16-2.93 (m, 5H).

Example 25.2-hydroxy-6-{[(3S)-4[2-(2-methoxyethyl)benzoyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 29

Compound 29 was synthesized according to Scheme 25.

Step 1

Into a 100-mL round-bottom flask, was placed 2-(2-methoxyethyl)benzoicacid (500.00 mg, 2.775 mmol, 1.00 equiv), DCM (20.00 mL),(3R)-morpholin-3-ylmethanol (325.04 mg, 2.775 mmol, 1.00 equiv), HATU(1582.51 mg, 4.162 mmol, 1.50 equiv), and DIEA (1075.81 mg, 8.324 mmol,3.00 equiv). The resulting solution was stirred for 3 hr at 25° C. Theresulting mixture was concentrated. The residue was purified by silicagel column with ethyl acetate/petroleum ether (1:1) as eluents. Thecollected fractions were combined and concentrated. This resulted in[(3R)-4-[2-(2-methoxyethyl)benzoyl]morpholin-3-yl]methanol. LCMS (ES)[M+1]⁺ m/z 280.2.

Step 2

Into a 50-mL round-bottom flask, was placed[(3R)-4-[2-(2-methoxyethyl)benzoyl]morpholin-3-yl]methanol (200.00 mg,0.716 mmol, 1.00 equiv), tetrahydrofuran (10 mL),2,6-dihydroxybenzaldehyde (98.89 mg, 0.716 mmol, 1.00 equiv),triphenylphosphine (225.36 mg, 0.859 mmol, 1.20 equiv), and DIAD (173.73mg, 0.859 mmol, 1.20 equiv). The resulting solution was stirred for 16hr at 25° C. The resulting mixture was concentrated. The crude reactionmixture was filtered and subjected to reverse phase preparative HPLC(Prep-C18, 20-45M, 120 g, Tianjin Bonna-Agela Technologies; gradientelution of 25% MeCN in water to 35% MeCN in water over a 10 min period,where both solvents contain 0.1% FA) to provide2-hydroxy-6-{[(3S)-4-[2-(2-methoxyethyl)benzoyl]morpholin-3-yl]methoxy}benzaldehyde.LCMS (ES) [M+1]⁺ m/z 400.2. ¹H NMR (300 MHz, DMSO-d6) δ 11.76 (br, 1H),10.31 (s, 1H), 7.56 (t, J=8.4 Hz, 1H), 7.46-6.90 (m, 4H), 6.8-6.455 (m,2H), 4.98-4.87 (m, 1H), 4.44-4.02 (m, 3H), 4.00-3.27 (m, 8H), 3.15-2.55(m, 4H).

Example 26.2-hydroxy-6-{[(3S)-4-[2-(2-methoxyethyl)benzoyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 30

Compound 30 was synthesized according to Scheme 26.

Step 1

Into a 50-mL round-bottom flask, was placed2-(2-cyanoethyl)pyridine-3-carboxylic acid (0.30 g, 1.70 mmol, 1.00equiv), HATU (777.0 mg, 2.04 mmol, 1.20 equiv), DMF (10.0 mL), DIEA(550.2 mg, 4.26 mmol, 2.50 equiv), and(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]pyrrolidine (403.50 mg,1.87 mmol, 1.10 equiv). The resulting solution was stirred for 2 hr atroom temperature. The reaction was then quenched by the addition ofwater (20 mL), extracted with 3×20 mL of ethyl acetate, dried overanhydrous sodium sulfate and concentrated. The residue was purified bysilica gel column chromatogrpahy with ethyl acetate/petroleum ether(0-60%) as eluents. This resulted(S)-3-(3-(2-(((tert-butyldimethylsilyl)oxy)methyl)pyrrolidine-1-carbonyl)pyridin-2-yl)propanenitrile.LCMS (ES, m/z): [M+H]^(±): 374.2.

Step 2

Into a 50-mL round-bottom flask, was placed(S)-3-(3-(2-(((tert-butyldimethylsilyl)oxy)methyl)-pyrrolidine-1-carbonyl)pyridin-2-yl)propanenitrile(0.4 g, 1.07 mmol, 1.0 equiv), THF (10 mL), and TBAF (1.2 mL, 1.20 mmol,1.1 equiv). The reaction solution was stirred for 2 hr at roomtemperature. The resulting mixture was concentrated and purified bysilica gel column chromatography with ethyl MeOH/DCM (6:94) as eluents.This resulted in(S)-3-(3-(2-(hydroxymethyl)pyrrolidine-1-carbonyl)pyridin-2-yl)propanenitrile.LCMS (ES, m/z): [M+H]⁺: 260.1.

Step 3

Into a 40-mL vial purged and maintained with an inert atmosphere ofnitrogen, was placed(S)-3-(3-(2-(hydroxymethyl)pyrrolidine-1-carbonyl)pyridin-2-yl)propanenitrile(120.00 mg, 0.46 mmol, 1.00 equiv), PPh₃ (145.6 mg, 0.56 mmol, 1.20equiv), THF (10 mL), and 1-(2,6-dihydroxyphenyl)ethanone (91.5 mg, 0.60mmol, 1.30 equiv). Then, DBAD (127.9 mg, 0.56 mmol, 1.20 equiv) wasdropwise at 0° C. After 20 min, the resulting solution was stirred at40° C. for overnight. The resulting mixture was concentrated. Theresidue was purified by silica gel column chromatography with ethylacetate/petroleum ether (0-90%) as eluents. The crude product waspurified by Prep-HPLC with the following conditions: Column, Kinetex EVOC18, 21.2*150 mm, 5 um; Mobile phase water (0.1% FA) and CH₃CN (40% upto 70% in 14 min); Detector, 220 nm. Flow rate, 20 mL/min. This resultedin2-hydroxy-6-{[(3S)-4-[2-(2-methoxyethyl)benzoyl]morpholin-3-yl]methoxy}benzaldehyde.LCMS: (ES, m/z): [M+H]⁺: 380.2. ¹H-NMR (300 MHz, DMSO-d6, ppm): δ11.68(s, 1H), 10.34 (s, 1H), 8.61 (dd, J=4.8, 1.7 Hz, 1H), 7.72 (dd, J=7.7,1.8 Hz, 1H), 7.54 (t, J=8.4 Hz, 1H), 7.38 (dd, J=7.7, 4.8 Hz, 1H), 6.72(d, J=8.4 Hz, 1H), 6.55 (d, J=8.4 Hz, 1H), 4.57-4.53 (m, 1H), 4.3-4.29(m, 2H), 4.10-3.59 (m, 1H), 3.32-3.14 (m, 2H), 3.06-3.01 (m, 2H),2.9-2.81 (m, 2H), 2.15-1.80 (m, 4H).

Example 27.3-{2-[(3S)-3-[(2-formyl-3-hydroxyphenoxy)methyl]morpholine-4-carbonyl]phenyl}propanenitrile,Compound 31

Compound 31 was synthesized according to Scheme 27.

Step 1

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed methyl 2-bromobenzoate (3.00 g,13.951 mmol, 1.00 equiv), acrylonitrile (1.48 g, 27.901 mmol, 2.00equiv), DIEA (5.41 g, 41.859 mmol, 3.00 equiv), dioxane (50.00 mL), andPd(P(t-Bu)₃)₂ (0.71 g, 1.389 mmol, 0.10 equiv). The resulting solutionwas stirred for 16 h at 100° C. in an oil bath. The resulting mixturewas concentrated. The residue was purified by silica gel column withethyl acetate/petroleum ether (10%EA) as eluents. This resulted inmethyl 2-[(1E)-2-cyanoeth-1-en-1-yl]benzoate. LCMS (ES) [M+1]⁺ m/z188.0.

Step 2

Into a 100-mL round-bottom flask, was placed methyl2-[(1E)-2-cyanoeth-1-en-1-yl]benzoate (1.90 g, 10.150 mmol, 1.00 equiv),MeOH (40.00 mL, 987.956 mmol, 97.34 equiv), and Pd/C (0.80 g, 7.517mmol, 0.74 equiv). The flask was evacuated and flushed three times withnitrogen, followed by flushing with hydrogen. The mixture was stirred 4h at room temperature under an atmosphere of hydrogen (balloon). Thesolids were filtered out. The filtrate was concentrated. This resultedin methyl 2-(2-cyanoethyl)benzoate. LCMS (ES) [M+1]⁺ m/z 190.1.

Step 3

Into a 100-mL round-bottom flask, was placed methyl2-(2-cyanoethyl)benzoate (1.90 g, 10.042 mmol, 1.00 equiv) and MeOH(50.00 mL). This was followed by the addition of a solution of LiOH(0.72 g, 30.065 mmol, 2.99 equiv) in H₂O (10 mL) at 0° C. in 5 min. Theresulting solution was stirred for 16 h at room temperature. The pHvalue of the solution was adjusted to 5 with citric acid (3 mol/L). Theresulting solution was extracted with 3×100 mL of DCM/MeOH=10:1. Themixture was dried over anhydrous sodium sulfate and concentrated undervacuum. This resulted in 2-(2-cyanoethyl)benzoic acid. LCMS (ES) [M−1]⁻m/z 174.3.

Step 4

Into a 20-mL sealed tube, was placed 2-(2-cyanoethyl)benzoic acid (0.50g, 2.854 mmol, 1.00 equiv), (3R)-morpholin-3-ylmethanol hydrochloride(0.66 g, 4.281 mmol, 1.50 equiv), HATU (1.63 g, 4.281 mmol, 1.50 equiv),DIEA (1.11 g, 8.588 mmol, 3.01 equiv), and DMF (10.00 mL). The resultingsolution was stirred for 2 h at room temperature. The resulting mixturewas concentrated. The residue was purified by silica gel columnchromatography with PE:THF (45% THF) as eluents. This resulted in3-[2-[(3R)-3-(hydroxymethyl)morpholine-4-carbonyl]phenyl]propanenitrile.LCMS (ES) [M+1]⁺ m/z 275.1.

Step 5

Into a 100-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed3-[2-[(3R)-3-(hydroxymethyl)morpholine-4-carbonyl]phenyl]propanenitrile(0.40 g, 1.458 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.40 g,2.916 mmol, 2 equiv), PPh₃ (0.76 g, 2.916 mmol, 2 equiv), and THF (30.00mL). The resulting solution was stirred for 15 min at 0° C. This wasfollowed by the addition of DIAD (0.59 g, 2.918 mmol, 2.00 equiv) at 0°C. in 3 min. The resulting solution was stirred for 2 h at roomtemperature. The resulting mixture was concentrated. The residue waspurified by silica gel column chromatography with PE/THF (22% THF) aseluents. The collected product was purified by Flash-Prep-HPLC(Prep-C18, 20-45M, 120 g, Tianjin Bonna-Agela Technologies; gradientelution of 45% MeCN in water to 65% MeCN in water over a 10 min period,where both solvents contain 0.1% FA). This resulted in3-{2-[(3S)-3-[(2-formyl-3-hydroxyphenoxy)methyl]morpholine-4-carbonyl]phenyl}propanenitrile.LCMS (ES) [M+1]⁺ m/z 395.2. ¹H NMR (300 MHz, DMSO-d₆, ppm) δ 11.73 (s,1H), 10.28 (s, 1H), 7.63-7.03 (m, 5H), 6.77 (d, J=8.3 Hz, 1H), 6.56 (d,J=8.5 Hz, 1H), 5.06-4.22 (m, 3H), 4.12-3.29 (m, 5H), 3.15-2.66 (m, 5H).

Example 28.3-{3-[(3S)-3-[(2-formyl-3-hydroxyphenoxy)methyl]morpholine-4-carbonyl]pyrazin-2-yl}propanenitrile,Compound 32

Compound 32 was synthesized according to Scheme 28.

Step 1

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed methyl3-bromopyrazine-2-carboxylate (6.00 g, 27.647 mmol, 1.00 equiv),acrylonitrile (4.40 g, 82.941 mmol, 3 equiv), DIEA (10.72 g, 82.941mmol, 3 equiv), dioxane (60.00 mL), and Pd(P(t-Bu)₃)₂ (1.41 g, 2.765mmol, 0.1 equiv). The resulting solution was stirred for 16 h at 100° C.in an oil bath. The resulting mixture was concentrated. The residue waspurified by silica gel column chromatography with (10%-20% EA) aseluents. This resulted in methyl3-[1E)-2-cyanoeth-1-en-1-yl]pyrazine-2-carboxylate. LCMS (ES) [M+1]⁺ m/z190.2.

Step 2

Into a 100-mL round-bottom flask, was placed methyl3-[(1E)-2-cyanoeth-1-en-1-yl]pyrazine-2-carboxylate (1.60 g, 8.458 mmol,1.00 equiv), MeOH (20.00 mL), and Pd/C (0.60 g, 5.638 mmol, 0.67 equiv).The flask was evacuated and flushed three times with nitrogen, followedby flushing with hydrogen. The resulting solution was stirred for 4 h atroom temperature under an atmosphere of hydrogen (balloon). The solidswere filtered out. The filtrate was concentrated. This resulted inmethyl 3-(2-cyanoethyl)pyrazine-2-carboxylate. LCMS (ES) [M+1]⁺ m/z192.2.

Step 3

Into a 100-mL round-bottom flask, was placed methyl3-(2-cyanoethyl)pyrazine-2-carboxylate (0.70 g, 3.661 mmol, 1.00 equiv)and MeOH (50 mL). This was followed by the addition of a solution ofLiOH.H₂O (0.31 g, 7.387 mmol, 2.02 equiv) in H₂O (10 mL) dropwise withstirring at 0° C. in 5 min The resulting solution was stirred for 2 h atroom temperature. The pH value of the solution was adjusted to 5 withcitric acid (2 mol/L). The resulting solution was extracted with 20×100mL of DCM/MeOH=10:1, and the organic layer was concentrated. Thisresulted in 3-(2-cyanoethyl)pyrazine-2-carboxylic acid. LCMS (ES) [M−1]⁻m/z 176.1.

Step 4

Into a 20-mL vial, was placed 3-(2-cyanoethyl)pyrazine-2-carboxylic acid(0.43 g, 2.427 mmol, 1.00 equiv), (3R)-morpholin-3-ylmethanolhydrochloride(0.34 g, 2.913 mmol, 1.2 equiv), HATU (1.11 g, 2.913 mmol,1.20 equiv), DIEA (0.94 g, 7.281 mmol, 3.00 equiv), and DMF (10.00 mL).The resulting solution was stirred for 2 h at room temperature. Theresulting mixture was concentrated. The residue was purified by silicagel column chromatography with PE/THF (50% THF) as eluents. Thisresulted in3-[3-[(3R)-3-(hydroxymethyl)morpholine-4-carbonyl]pyrazin-2-yl]propanenitrile.LCMS (ES) [M+1]⁺ m/z 277.1.

Step 5

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed3-[3-[(3R)-3-(hydroxymethyl)morpholine-4-carbonyl]pyrazin-2-yl]propanenitrile(200.00 mg, 0.724 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (199.96mg, 1.448 mmol, 2.00 equiv), PPh₃ (379.72 mg, 1.448 mmol, 2.00 equiv),and THF (20.00 mL). The resulting solution was stirred for 15 min at 0°C. This was followed by the addition of DIAD (292.74 mg, 1.448 mmol,2.00 equiv) dropwise with stirring at 0° C. in 5 min The resultingsolution was stirred for 2 h at room temperature. The resulting mixturewas concentrated. The residue was purified by silica gel columnchromatography with PE/THF (35% THF) as eluents. The collected productwas further purified by Flash-Prep-HPLC (Prep-C18, 20-45M, 120 g,Tianjin Bonna-Agela Technologies; gradient elution of 35% MeCN in waterto 60% MeCN in water over a 10 min period, where both solvents contain0.1% FA). This resulted in3-[3-(3S)-3-(2-formyl-3-hydroxyphenoxymethyl)morpholine-4-carbonyllpyrazin-2-yl]propanenitrile.LCMS (ES) [M+1]⁺ m/z 397.2. ¹H NMR (300 MHz, DMSO-d₆, ppm) δ 11.75 (s,1H), 10.32 (s, 1H), 8.72 (dd, J=8.2, 2.5 Hz, 1H), 8.55 (dd, J=13.7, 2.5Hz, 1H), 7.62-7.51 (m, 1H), 6.80-6.48 (m, 2H), 5.03-4.94 (m, 1H),4.53-4.31 (m, 2H), 4.12-3.38 (m, 5H), 3.21-3.04 (m, 3H), 2.99-2.90 (m,2H).

Example 29.2-hydroxy-6-{[(3S)-4-[3-(hydroxymethyl)pyrazine-2-carbonyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 33

Compound 33 was synthesized according to Scheme 29.

Step 1

Into a 250-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed methyl 3-bromopyrazine-2-carboxylate(5.00 g, 23.039 mmol, 1.00 equiv), H₂O (100.00 mL). This was followed bythe addition of NaBH₄ (4.36 g, 115.243 mmol, 5.00 equiv) in severalbatches at 0° C. The resulting solution was stirred for overnight atroom temperature. The reaction was quenched by the addition of 50 mL ofEtOH and diluted with 150 mL of K₂CO₃(_(aq)) . The,n the mixture wasstirred for 0.5 h at room temperature. The resulting solution wasextracted with 3×150 mL of ethyl acetate and extracted with 3×150 mL ofdichloromethane; the organic layer was dried over anhydrous sodiumsulfate and concentrated. This resulted in(3-bromopyrazin-2-yl)methanol. LCMS (ES) [M+1]⁺ m/z 189.1.

Step 2

Into a 100-mL round-bottom flask, was placed(3-bromopyrazin-2-yl)methanol (3.00 g, 15.872 mmol, 1.00 equiv), DCM(60.00 mL), imidazole (2.16 g, 31.729 mmol, 2.00 equiv), and TBSC1 (2.87g, 19.042 mmol, 1.20 equiv). The resulting solution was stirred for 3 hat room temperature and diluted with 50 mL of H₂O. The resultingsolution was extracted with 3×150 mL of dichloromethane; the organiclayer was dried over anhydrous sodium sulfate and concentrated. Theresidue was purified by silica gel column chromatography with ethylacetate/petroleum ether (20% EA) as eluents. This resulted in2-bromo-3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine. LCMS (ES)[M+1]⁺ m/z 303.1.

Step 3

Into a 250-mL pressure tank reactor, was placed2-bromo-3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine (6.00 g, 19.784mmol, 1.00 equiv), Pd(dppf)Cl₂ (1.45 g, 1.978 mmol, 0.10 equiv), TEA(6.01 g, 59.352 mmol, 3.00 equiv), MeOH (100.00 mL), and CO (gas). Theresulting solution was stirred for overnight at 90° C. The resultingmixture was concentrated. The residue was purified by silica gel columnchromatograhy with PE/THF (70% THF) as eluents. This resulted in methyl3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine-2-carboxylate. LCMS(ES) [M+1]⁺ m/z 283.2.

Step 4

Into a 250-mL round-bottom flask, was placed methyl3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine-2-carboxylate (3.10 g,10.977 mmol, 1.00 equiv), methanol (50.00 mL). This was followed by theaddition of a solution of Li)H.H₂O (0.92 g, 21.924 mmol, 2.00 equiv) inH₂O (10 mL) dropwise with stirring at 0° C. in 5 min. The resultingsolution was stirred for 5 h at room temperature. The pH value of thesolution was adjusted to 5 with citric acid (2 mol/L). The resultingsolution was extracted with 5×150 mL of dichloromethane; the organiclayer was dried over anhydrous sodium sulfate and concentrated. Thisresulted in3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine-2-carboxylic acid. LCMS(ES) [M+1]⁺ m/z 269.2.

Step 5

Into a 20-mL vial, was placed3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine-2-carboxylic acid (1.00g, 3.726 mmol, 1.00 equiv), (3R)-morpholin-3-ylmethanol hydrochloride(0.68 g, 4.471 mmol, 1.20 equiv), dimethylformamide (10.00 mL), HATU(1.70 g, 4.471 mmol, 1.20 equiv), and DIEA (1.95 mL, 15.064 mmol, 3.00equiv). The resulting solution was stirred for 3 h at room temperature.The resulting solution was diluted with 50 mL of H₂O. The resultingsolution was extracted with 4×60 mL of dichloromethane, and the organiclayer was washed with 2×100 mL of brine. The mixture was dried overanhydrous sodium sulfate and concentrated. The residue was purified bysilica gel column chromatography with PE/THF (60% THF) as eluents. Thisresulted in[(3R)-4-(3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine-2-carbonyl)morpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z 368.2.

Step 6

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed[(3R)-4-(3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine-2-carbonyl)morpholin-3-yl]methanol(0.97 g, 2.639 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.73 g,5.279 mmol, 2.00 equiv), PPh₃ (1.38 g, 5.261 mmol, 1.99 equiv), and THF(60 mL). The resulting solution was stirred for 15 min at 0° C. This wasfollowed by the addition of DIAD (1.07 g, 5.279 mmol, 2.00 equiv)dropwise with stirring at 0° C. in 2 min The resulting solution wasstirred for 2 h at room temperature. The resulting mixture wasconcentrated. The residue was purified by silica gel column with PE/THF(50% THF) as eluents. This resulted in2-[[(3S)-4-(3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine-2-carbonyl)morpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z 488.2.

Step 7

Into a 100-mL round-bottom flask, was placed2-[[(3S)-4-(3-[[(tert-butyldimethylsilyl)oxy]methyl]pyrazine-2-carbonyl)morpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(0.8 g, 1.641 mmol, 1.00 equiv), THF (20.00 mL), and TBAF (2.5 mL, 1.5equiv, 2M). The resulting solution was stirred for 2 h at roomtemperature. The resulting mixture was concentrated. The residue waspurified by silica gel column chromatography with (60% THF) as eluents.The collected product was further purified by Flash-Prep-HPLC (Prep-C18,20-45M, 120 g, Tianjin Bonna-Agela Technologies; gradient elution of 30%MeCN in water to 50% MeCN in water over a 10 min period, where bothsolvents contain 0.1% FA). This resulted in2-hydroxy-6-{[(3S)-4-[3-(hydroxymethyl)pyrazine-2-carbonyl]morpholin-3-yl]methoxy}benzaldehyde.LCMS (ES) [M+1]⁺ m/z 374.1. ¹H-NMR (300 MHz, DMSO-d₆,ppm) δ 11.79 (s,1H), 10.29 (d, J=3.6 Hz, 1H), 8.64 (t, J=2.4 Hz, 1H), 8.54 (dd, J=12.2,2.6 Hz, 1H), 7.62-7.49 (m, 1H), 6.77-6.48 (m, 2H), 5.72-5.51 (m, 1H),4.95-4.30 (m, 5H), 4.12-3.39 (m, 5H), 3.24-2.97 (m, 1H).

Example 30.2-{[(2S)-1-[2-(1,2-dihydroxyethyl)benzoyl]piperidin-2-yl]methoxy}-6-hydroxybenzaldehyde,Compound 34

Compound 34 was synthesized according to Scheme 30.

Step 1

Into a 100-mL 3-necked round-bottom flask, was placed o-bromobenzoicacid (5.0 g, 24.87 mmol, 1.0 equiv),(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine (6.90 g, 30.07mmol, 1.2 equiv), DCM (50.0 mL), and DIEA (6.50 g, 50.29 mmol, 2.0equiv). This was followed by the addition of HATU (11.40 g, 29.98 mmol,1.2 equiv) at 0° C. The reaction solution was stirred for 2 h at roomtemperature. The reaction was then quenched by the addition of water (30mL), and extracted with 2×50 mL of dichloromethane. The residue waspurified by silica gel column with ethyl acetate/petroleum ether (10%)as eluents.(S)-(2-bromophenyl)(2-(((tert-butyldimethylsilyl)oxy)methyl)piperidin-1-yl)methanonewas obtained. LCMS (ES) [M+1]⁺ m/z: 412.

Step 2

Into a 250-mL round-bottom flask, was placed(S)-(2-bromophenyl)(2-(((tert-butyldimethylsilyl)oxy)methyl)piperidin-1-yl)methanone(5.0 g, 12.12 mmol, 1.0 equiv), THF (50 mL), and 1 M TBAF in THF (12.1mL, 12.12 mmol, 1.0 equiv). The mixture was stirred for 2 h at roomtemperature. The mixture was concentrated to remove the solvent, and theresidue was purified by silica gel column with ethyl acetate (100%) aseluents. This resulted in(S)-(2-bromophenyl)(2-(hydroxymethyl)piperidin-1-yl)methanone. LCMS (ES)[M+1]⁺ m/z: 298.

Step 3

Into a 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed(S)-(2-bromophenyl)(2-(hydroxymethyl)piperidin-1-yl)methanone (2.0 g,6.71 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (1.12 g, 8.11 mmol, 1.2equiv), THF (80 mL), and PPh₃ (2.10 g, 8.01 mmol, 1.2 equiv). This wasfollowed by the addition of DIAD (1.63 g, 8.05 mmol, 1.2 equiv) at 0° C.The reaction solution was stirred overnight at room temperature. Thesolution was concentrated to remove the solvent, and the residue waspurified by silica gel column with ethyl acetate/petroleum ether (80%)as eluents. This resulted in(S)-2-((1-(2-bromobenzoyl)piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z: 418.

Step 4

Into a 50-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed(S)-2-((1-(2-bromobenzoyl)piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde(1.57 g, 3.75 mmol, 1.0 equiv), dioxane (20 mL),tributyl(ethenyl)stannane (2.40 g, 7.54 mmol, 2.0 equiv), andPd(dppf)Cl₂ (307 mg, 0.37 mmol, 0.10 equiv). The mixture was stirredovernight at 90° C. The mixture was concentrated to remove the solvent,and the residue was purified by silica gel column chromatography withethyl acetate/petroleum ether (1/1) as eluents. This resulted in(S)-2-hydroxy-6-((1-(2-vinylbenzoyl)piperidin-2-yl)methoxy)benzaldehyde.LCMS (ES) [M+1]⁺ m/z: 366.

Step 5

Into a 20-mL vial, was placed(S)-2-hydroxy-6-((1-(2-vinylbenzoyl)piperidin-2-yl)methoxy)benzaldehyde(604 mg, 1.65 mmol, 1.0 equiv), t-BuOH (4.0 mL), H₂O (4.0 mL), andad-mix-alpha (2.60 g, 4.96 mmol, 3.0 equiv). The mixture was stirred for3 h at room temperature. The crude product was purified by Prep-HPLCwith the following conditions (SHIMADZU (HPLC-01)): Column, Kinetex EVOC18 Column, 21.2*150, 5 um, mobile phase, Water (0.1% FA) and CH₃CN (45%Phase B up to 65% in 9 min), Detector, UV 254 nm.2-{[(2S)-1-[2-(1,2-dihydroxyethyl)benzoyl]piperidin-2-yl]methoxy}-6-hydroxybenzaldehydewas obtained. LCMS: (ES, m/z): [M+1]⁺: 400.2. ¹H-NMR: (300 MHz, DMSO-d₆,ppm): δ11.73 (s, 1H), 10.26 (s, 1H), 7.59-7.20 (m, 5H), 6.88-6.53(m,2H), 5.26-4.27 (m, 6H), 3.55-3.05 (m, 4H), 1.94-1.43 (m, 6H).

Example 31.2-{[(3R)-4-{2-[(1S)-1,2-dihydroxyethyl]benzoyl}thiomorpholin-3-yl]methoxy}-6-hydroxybenzaldehydeand2-{[(3R)-4-{2-[(1R)-1,2-dihydroxyethyl]benzoyl}thiomorpholin-3-yl]methoxy}-6-hydroxybenzaldehyde

Compound 35, Diastereomer 1 and Compound 35, Diasteroemer 2 weresynthesized according to Scheme 31.

Step 1

Into a 100-mL round-bottom flask, was placed2-(2,2-dimethyl-1,3-dioxolan-4-yl)benzoic acid (900 mg, 4.05 mmol, 1.00equiv), DMF (10.0 mL), (3R)-thiomorpholin-3-ylmethanol (593 mg, 4.45mmol, 1.10 equiv), and DIEA (1.05 g, 8.09 mmol, 2.00 equiv). This wasfollowed by the addition of HATU (2.31 g, 6.07 mmol, 1.50 equiv) at 0°C. The resulting solution was stirred for 2 hr at room temperature. Theresulting solution was diluted with 50 mL of H₂O and extracted with 3×30mL of ethyl acetate, and the organic layers were combined, dried overanhydrous sodium sulfate, and concentrated. The residue was purified bysilica gel column chromatography with ethyl acetate/petroleum ether(1/10) as eluents. This resulted in[(3R)-4-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)benzoyl]thiomorpholin-3-yl]methanol.[M+1]⁺ m/z: 338.1.

Step 2

Into a 50-mL round-bottom flask, was placed[(3R)-4-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)benzoyl]thiomorpholin-3-yl]methanol(620 mg, 1.83 mmol, 1.00 equiv), DCE (8.0 mL), and DIEA (1.42 g, 11.02mmol, 6.00 equiv). This was followed by the addition of MsCl (420 mg,3.67 mmol, 2.00 equiv) dropwise with stirring at 0° C. The resultingsolution was stirred for 1 hr at room temperature. To this solution wasadded 2,6-dihydroxybenzaldehyde (253 mg, 1.83 mmol, 1.00 equiv). Theresulting solution was stirred for 6 hr at 80° C. The reaction mixturewas cooled and concentrated. The resulting solution was diluted with 5mL of ACN. The crude product was purified by Flash-Prep-HPLC with thefollowing conditions (IntelFlash-1): Column, C18 silica gel; mobilephase, H₂O (0.1%HCOOH)/ACN=1/1 increasing to H₂O(0.1% HCOOH)/ACN=1/2within 10 min; Detector, UV 254 nm. This resulted in2-[[(3R)-4-[2-(2,2-dimethyl-1,3-dioxolan-4-yl)benzoyl]thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.[M+1]⁺ m/z: 458.2.

Step 3

2-hydroxy-6-[[(3R)-4-[2-(2-methyl-1,3-dioxolan-4-yl)benzoyl]thiomorpholin-3-yl]methoxy]benzaldehyde was purified by Chiral-Prep-HPLC with the followingconditions: Mobile phase A: n-Hexane; Mobile phase B:EtOH; Flow rate: 20mL/min; Column: DAICEL CHIRALPAK ID, 250*20 mm, 5 um; Gradient:5% B in20 min; Detector, UV 254 nm. The collected products were subjected toanalytical chiral HPLC analysis (Instrument Name: Shimadzu LC-20AD;Mobile Phase A: n-Hexane; Mobile Phase B: Ethanol; Column: CHIRALPAKIC-3, 50*4.6 mm, 3um IC30CC-SC002).This resulted in Compound 31d,Diastereomer 2 (Analytical HPLC Retention Time=2.188 min) and Compound31d, Diastereomer 1 (Analytical HPLC Retention Time=2.988 min).

Step 4A: Compound 35, Diastereomer 1

Into a 50-mL round-bottom flask, was placed Compound 31, Diastereomer 1(80 mg, 0.17 mmol, 1.00 equiv), ACN (2.0 mL), Yb(OTf)₃.H₂O (54 mg, 0.08mmol, 0.50 equiv). The resulting solution was stirred for 5 hr at roomtemperature. The resulting solution was diluted with 5 mL of ACN andfiltered. The crude product was purified by Prep-HPLC with the followingconditions (2#SHIMADZU (HPLC-01)): Column, Welch Xtimate C18, 21.2*250mm,5 um; mobile phase, Water and ACN (15% Phase B up to 70% in 20 min);Detector, UV 254 nm. The product was analyzed by chiral SFC (InstrumentName: Shimadzu LC-30AD SF; Column: AS-3, 100*3 mm). This resulted inCompound 35, Diastereomer 1. SFC retention time=2.75 min LCMS [M+1]⁺m/z:418.2. ¹H NMR (300 MHz, DMSO-d₆) δ 11.76 (br, 1H), 10.43-10.06 (m, 1H),7.64-6.88 (m, 5H), 6.87-6.45 (m, 2H), 5.57-5.15 (m, 2H), 4.93-4.37 (m,4H), 3.68-3.37 (m, 3H), 3.24-2.83 (m, 2H), 2.83-2.59 (m, 2H), 2.48-2.22(m, 1H).

Step 4B: Compound 35, Diastereomer 2

Into a 50-mL round-bottom flask was placed Compound 31d, Diastereomer 2(90 mg, 0.19 mmol, 1.00 equiv), ACN (2.0 mL), and Yb(OTf)₃.H₂O (61 mg,0.09 mmol, 0.50 equiv). The resulting solution was stirred for 5 hr atroom temperature. The resulting solution was diluted with 5 mL of ACNand filtered. The crude product was purified by Prep-HPLC with thefollowing conditions (2#SHIMADZU (HPLC-01)): Column, Welch Xtimate C18,21.2*250 mm,5 um; mobile phase, Water and ACN (15% Phase B up to 70% in18 min); Detector, UV 254 nm. The product was analyzed by chiral SFC(Instrument Name: Shimadzu LC-30AD SF; Column: AS-3, 100*3 mm). Thisresulted in Compound 35, Diastereomer 2. SFC retention time=2.44 minLCMS [M+1]⁺ m/z: 418.2. ¹H NMR (300 MHz, DMSO-d₆) δ 11.76 (br, 1H),10.46-10.03 (m, 1H), 7.70-6.90 (m, 5H), 6.82-6.48 (m, 2H), 5.52-5.15 (m,2H), 4.93-4.02 (m, 4H), 3.63-3.36 (m, 3H), 3.26-2.90 (m, 2H), 2.88-2.55(m, 2H), 2.48-2.24 (m, 1H).

Example 32.2-{[(2S)-1-[2-(1,2-dihydroxyethyDpyridine-3-carbonyl]piperidin-2-yl]methoxy}-6-hydroxybenzaldehyde,Compound 36

Compound 36 was synthesized according to Scheme 32.

Step 1

Into a 100-mL 3-necked round-bottom flask, was placed2-bromopyridine-3-carboxylic acid (4.0 g, 19.80 mmol, 1.0 equiv),(2S)-2-[[(tert-butyldimethylsilyl)oxy]methyl]piperidine (5.50 g, 23.97mmol, 1.2 equiv), DCM (50 mL), and DIEA (5.13 g, 39.70 mmol, 2.0 equiv).This was followed by the addition of HATU (9.07 g, 23.85 mmol, 1.2equiv) at 0° C. The reaction solution was stirred for 2 h at roomtemperature. The reaction was then quenched by the addition of water (50mL), and extracted with 2×50 mL of dichloromethane. The combined organicphase was dried over anhydrous sodium sulfate and filtered, and thefiltrate was concentrated under reduced pressure. The residue waspurified by silica gel column with ethyl acetate/petroleum ether (1/4).(S)-(2-bromopyridin-3-yl)(2-(((tert-butyldimethylsilyl)oxy)methyl)piperidin-1-yl)methanonewas obtained. LCMS (ES) [M+1]⁺ m/z: 413.

Step 2

Into a 250-mL round-bottom flask, was placed(S)-(2-bromopyridin-3-yl)(2-(((tert-butyldimethylsilyl)oxy)methyl)piperidin-1-yl)methanone(8.0 g, 19.35 mmol, 1.0 equiv), THF (80 mL), and TBAF (1 M in THF) (20mL, 20.0 mmol, 1.0 eq). The mixture was stirred for 2 h at roomtemperature and concentrated to remove the solvent. The residue waspurified by silica gel column chromatography with ethyl acetate (100%)as eluents. This resulted in(S)-(2-bromopyridin-3-yl)(2-(hydroxymethyl)piperidin-1-yl)methanone.LCMS (ES) [M+1]⁺ m/z: 299.

Step 3

Into a 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed(S)-(2-bromopyridin-3-yl)(2-(hydroxymethyl)piperidin-1-yl)methanone (2.0g, 6.69 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (1.10 g, 7.96 mmol,1.2 equiv), PPh₃ (2.10 g, 8.01 mmol, 1.2 equiv), and THF (80 mL). Thiswas followed by the addition of DIAD (1.63 g, 8.06 mmol, 1.2 equiv) at0° C. After addition, the resulting solution was stirred overnight atroom temperature. The mixture was concentrated to remove the solvent,and the residue was purified by silica gel column chromatography withethyl acetate/petroleum ether (1/1) as eluents. This resulted in2-(S)-2-((1-(2-bromonicotinoyl)piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z: 419.

Step 4

Into a 100-mL round-bottom flask purged and maintained with an inertatmosphere of nitrogen, was placed2-(S)-2-((1-(2-bromonicotinoyl)piperidin-2-yl)methoxy)-6-hydroxybenzaldehyde(3.20 g, 7.63 mmol, 1.0 equiv), dioxane (30 mL),tributyl(ethenyl)stannane (4.85 g, 15.30 mmol, 2.0 equiv), andPd(dppf)Cl₂.CH₂Cl₂ (624 mg, 0.76 mmol, 0.10 equiv). The mixture wasstirred overnight at 90° C. After cooling to room temperature, thereaction solution was concentrated to remove the solvent, and theresidue was purified by silica gel column chromatography with ethylacetate/petroleum ether (1/1) as eluents. This resulted in(S)-2-hydroxy-6-((1-(2-vinylnicotinoyl)piperidin-2-yl)methoxy)benzaldehyde.LCMS (ES) [M+1]⁺ m/z: 367.

Step 5

Into a 100-mL round-bottom flask, was placed(S)-2-hydroxy-6-((1-(2-vinylnicotinoyl)piperidin-2-yl)methoxy)benzaldehyde(500 mg, 1.37 mmol, 1.0 equiv), t-BuOH (20.0 mL), H₂O (20.0 mL), andAD-mix-alpha (5.31 g, 6.82 mmol, 5.0 equiv). The mixture was stirredovernight at room temperature. The mixture was concentrated to removethe solvent, and the crude product was purified by Prep-HPLC with thefollowing conditions (SHIMADZU (HPLC-01): Column, Kinetex EVO C18Column, 21.2*150, 5 um, mobile phase, Water (0.1% FA) and CH3CN (45%Phase B up to 65% in 9 min), Detector, UV 254 nm. This resulted in2-{[(2S)-1-[2-(1,2-dihydroxyethyl)pyridine-3-carbonyl]piperidin-2-yl]methoxy}-6-hydroxybenzaldehyde.LCMS: (ES, nilz): [M+H]⁺: 401.2. ¹H-NMR (300 MHz, DMSO-d6, ppm): 611.82-11.66 (m, 1H), 10.34-10.14 (m, 1H), 8.56 (d, 1H, J=1.8 Hz),7.68-7.31 (m, 3H), 6.78-6.54 (m, 2H), 5.22-5.19 (m, 2H), 4.71-4.29 (m,4H), 3.68-3.58 (m, 2H), 3.19-2.90(m, 2H), 2.08-1.50(m, 6H).

Example 33.2-hydroxy-6-{[(3R)-4-[2-(2-hydroxyethyl)pyridine-3-carbonyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 37

Compound 37 was synthesized according to Scheme 33.

Step 1

Into a 50-mL 3-necked round-bottom flask, was placed2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carboxylic acid(1.50 g, 5.33 mmol, 1.0 equiv), (3S)-morpholin-3-ylmethanolhydrochloride (980 mg, 6.38 mmol, 1.2 equiv), DCM (15 mL), and DIEA(2.07 g, 16.02 mmol, 3.0 equiv). HATU (2.40 g, 6.31 mmol, 1.2 equiv) wasadded by 3 batches at 0° C. After addition, the mixture was stirred for2 h at room temperature. The reaction was then quenched by the additionof water (20 mL), and extracted with 3×20 mL of dichloromethane. Thecombined organic phase was dried over anhydrous sodium sulfate andfiltered, and the filtrate was concentrated under reduced pressure. Theresidue was purified by silica gel column chromatography with ethylacetate/petroleum ether (80%) as eluents. This resulted in(S)-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone.LCMS (ES) [M+1]⁺ m/z: 381.

Step 2

Into a 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed(S)-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone(1.98 g, 5.20 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (863 mg, 6.25mmol, 1.2 equiv), PPh₃ (1.64 g, 6.25 mmol, 1.2 equiv), and THF (80 mL).After cooling to 0° C., DBAD (1.44 g, 6.25 mmol, 1.2 equiv) was added inone portion. The mixture was stirred overnight at room temperature. Themixture was concentrated to remove the solvent, and the residue waspurified by silica gel column chromatography with ethylacetate/petroleum ether (80%) as eluents. This resulted in(R)-2-((4-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)nicotinoyl)morpholin-3-yl)methoxy)-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z: 501.

Step 3

Into a 20-mL vial, was placed(R)-2-((4-(2-(2-((tert-butyldimethylsilyl)oxy)ethyl)nicotinoyl)morpholin-3-yl)methoxy)-6-hydroxybenzaldehyde(300 mg, 0.60 mmol, 1.0 equiv), CH₃CN (5.0 mL), and HCOOH (1.0 mL). Thereaction solution was stirred for 1 h at 50° C. and then concentrated toremove the solvent. The residue was purified by Prep-HPLC with thefollowing conditions: Kinetex EVO C18 column, 21.2*150, 5 um, mobilephase, Water (0.1% FA) and CH3CN (10% Phase B up to 50% within 15 min),detector, UV 254 nm. This resulted in2-hydroxy-6-{[(3R)-4-[2-(2-hydroxyethyl)pyridine-3-carbonyl]morpholin-3-yl]methoxy}benzaldehyde.LCMS (ES, m/z): [M+H]⁺: 387.1. ¹H-NMR (300 MHz, DMSO-d₆, ppm): δ 11.74(br, 1H), 10.33-10.12 (m, 1H), 8.56 (dd, J=4.8, 1.8 Hz, 1H), 7.71-7.29(m, 3H), 6.78-6.52 (m, 2H), 5.03-4.89 (m, 1H), 4.65-4.34 (m, 3H),4.11-3.34 (m, 7H), 3.11-2.84 (m, 3H).

Example 34.2-hydroxy-6-{[(2R)-1-[2-(2-hydroxyethyl)pyridine-3-carbonyl]piperidin-2-yl]methoxy}benzaldehyde,Compound 38

Compound 38 was synthesized according to Scheme 34.

Step 1

Into a 50-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carboxylic acid(1.00 g, 3.55 mmol, 1.00 equiv), DMF (25.0 mL),(2R)-piperidin-2-ylmethanol (491 mg, 4.26 mmol, 1.20 equiv), and DIEA(551 mg, 4.26 mmol, 1.20 equiv). This was followed by the addition ofHATU (1.62 g, 4.26 mmol, 1.2 equiv) in several batches at 0° C. Thereaction solution was stirred overnight at room temperature. Thereaction was diluted with 30 mL of H₂O and extracted with 3×100 mL ofethyl acetate. The combined organic phase was washed with 1×50 mL ofbrine and dried over anhydrous sodium sulfate. The mixture was filtered,and the filtrate was concentrated under reduced pressure. The residuewas purified by silica gel column chromatography with ethylacetate/petroleum ether (1:2) as eluents. This resulted in[(2R)-1-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)piperidin-2-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 379.

Step 2

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed[(2R)-1-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)piperidin-2-yl]methanol(1.20 g, 3.17 mmol, 1.00 equiv), THF (50.0 mL),2,6-dihydroxybenzaldehyde (525 mg, 3.80 mmol, 1.20 equiv), and PPh₃ (998mg, 3.80 mmol, 1.20 equiv). This was followed by the addition of asolution of DIAD (769 mg, 3.80 mmol, 1.20 equiv) in THF (2.00 mL)dropwise with stirring at 0° C. The reaction solution was stirredovernight at room temperature. After concentrating under reducedpressure, the residue was purified by silica gel column chromatographywith ethyl acetate/petroleum ether (1:1) as eluents. This resulted in2-[[(2R)-1-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)piperidin-2-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z: 499.

Step 3

Into a 50-mL round-bottom flask, was placed2-[[(2R)-1-(2-[2-[(tert-butyldimethylsilyl)oxy]ethyl]pyridine-3-carbonyl)piperidin-2-yl]methoxy]-6-hydroxybenzaldehyde(300 mg, 0.60 mmol, 1.00 equiv), CH₃CN (5.00 mL), and HCOOH (1.00 mL).The mixture was stirred for 3 h at 50° C. in oil bath. The reactionmixture was cooled to room temperature and concentrated under reducedpressure. The crude product was purified by Flash-Prep-HPLC with thefollowing conditions (IntelFlash-1): Column Ascentis Express C18, 50*3.0mm, 2.7 um, Mobile Phase A: Water/0.05% FA, Mobile Phase B: CH₃CN; Flowrate: 1.5 mL/min, Gradient: 5% B to 100% B in 1.2 min, hold 0.6 min.This resulted in2-hydroxy-6-{[(2R)-1-[2-(2-hydroxyethyl)pyridine-3-carbonyl]piperidin-2-yl]methoxy}benzaldehyde.LCMS (ES, m/z): [M+H]⁺: 385. ¹H-NMR (300 MHz, DMSO-d₆, ppm): δ 11.73(br, 1H), 10.22 (s, 1H), 8.54 (s, 1H), 7.69-7.23 (m, 3H), 6.75 (d, J=8.4Hz, 2H), 5.21-5.20 (m, 1H), 4.65-4.27 (m, 3H), 3.78-3.65 (m, 2H),3.20-2.68 (m, 4H), 1.95-1.39 (m, 6H).

Example 35.2-hydroxy-6-{[(3S)-4-[2-(2-hydroxy-2-methylpropyl)pyridine-3-carbonyl]morpholin-3-yl]methoxy}benzaldehyde,Compound 39

Compound 39 was synthesized according to Scheme 35.

Step 1

Into a 1-L 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed 3-bromo-2-methylpyridine (20.0g, 116.26 mmol, 1.0 equiv) and THF (400 mL). This was followed by theaddition of LDA (2M in THF) (69.8 mL, 139.51 mmol, 1.2 equiv) at −78° C.and stirred for 0.5 h. To this was added acetone (7.46 g, 128.45 mmol,1.1 equiv) at the same temperature. The mixture was stirred for 1 hr at−78° C. The reaction was then quenched by the addition of NH₄Cl_((aq))(300 mL) and extracted with 3×500 mL of ethyl acetate. The combinedorganic phase was dried over anhydrous sodium sulfate and filtered, andthe filtrate was concentrated under reduced pressure. The residue waspurified by silica gel column chromatography with ethylacetate/petroleum ether (15%) as eluents. This resulted in1-(3-bromopyridin-2-yl)-2-methylpropan-2-ol. LCMS (ES) [M+1]⁺ m/z: 230.

Step 2

Into a 250-mL round-bottom flask, was placed1-(3-bromopyridin-2-yl)-2-methylpropan-2-ol (4.0 g, 17.38 mmol, 1.0equiv), TBSC1 (3.10 g, 20.86 mmol, 1.2 eq), DMF (40 mL), imidazole (2.38g, 34.76 mmol, 2.0 eq), and DMAP (212 mg, 1.74 mmol, 0.10 equiv). Thereaction solution was stirred 24 h at 60° C. After cooling to roomtemperature, the reaction was then quenched by the addition of water (50mL) and extracted with 3×50 mL of ethyl acetate. The combined organicphase was washed with 2×50 mL of brine and dried over anhydrous sodiumsulfate. The mixture was filtered, and the filtrate was concentratedunder reduced pressure; the residue was purified by silica gel columnchromatography with ethyl acetate/petroleum ether (1/20) as eluents.This resulted in3-bromo-2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)pyridine.LCMS (ES) [M+1]⁺ m/z: 344.

Step 3

Into a 250-mL pressure tank reactor, was placed3-bromo-2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)pyridine(4.18 g, 12.14 mmol, 1.0 equiv), MeOH (80 mL), TEA (2.45 g, 24.28 mmol,2.0 equiv), and Pd(dppf)Cl₂CH₂Cl₂ (495 mg, 0.61 mmol, 0.05 eq). Themixture was stirred for 12 h at 130° C. under CO_((g)) atmosphere at 30atm. The mixture was concentrated to remove the solvent; the residue waspurified by silica gel column chromatography with ethylacetate/petroleum (1/3) as eluents. This resulted in methyl2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)nicotinate. LCMS (ES)[M+1]⁺ m/z: 324.

Step 4

Into a 50-mL round-bottom flask, was placed methyl2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)nicotinate (2.0 g,6.18 mmol, 1.0 equiv), MeOH (16 mL), and H₂O (8 mL). This was followedby the addition of LiOH (520 mg, 12.26 mmol, 2.0 equiv) at 0° C. Themixture was stirred for 2 h at 50° C. After cooling to room temperature,the pH value of the solution was adjusted to 7 with citric acid. Thesolids were collected by filtration and dried under infrared lamp. Thisresulted in 2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)nicotinicacid. LCMS (ES) [M+1]⁺ m/z: 310.

Step 5

Into a 50-mL 3-necked round-bottom flask, was placed2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)nicotinic acid (1.60g, 5.17 mmol, 1.0 equiv), (3R)-morpholin-3-ylmethanol hydrochloride (951mg, 6.19 mmol, 1.2 equiv), DMF (16 mL), and DIEA (2.0 g, 15.48 mmol, 3.0equiv). This was followed by the addition of HATU (2.36 g, 6.21 mmol,1.20 equiv) at 0° C. The reaction solution was stirred for 2 h at roomtemperature. The reaction was then quenched by the addition of water (30mL) and extracted with 3×30 mL of ethyl acetate. The combined organicphase was washed with brine (30 mL×3) and dried over anhydrous sodiumsulfate. The mixture was filtered, and the filtrate was concentratedunder reduced pressure. The residue was purified by silica gel columnchromatography with ethyl acetate/petroleum ether (1/1) as eluents. Thisresulted in(R)-(2-(2-((tert-butyldimethylsilyeoxy)-2-methylpropyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone.LCMS (ES) [M+1]⁺ m/z: 409.

Step 6

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed(R)-(2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)pyridin-3-yl)(3-(hydroxymethyl)morpholino)methanone(1.0 g, 2.45 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (406 mg, 2.94mmol, 1.2 equiv), PPh₃ (770 mg, 2.94 mmol, 1.2 equiv), and THF (50 mL).This was followed by the addition of DIAD (594 mg, 2.94 mmol, 1.2 equiv)at 0° C. The mixture was stirred overnight at room temperature. Themixture was concentrated to remove the solvent, and the residue waspurified by silica gel column chromatography with ethylacetate/petroleum ether (1/1). This resulted in(S)-2-((4-(2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)nicotinoyl)morpholin-3-yl)methoxy)-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z: 529.

Step 7

Into a 20-mL vial, was placed(S)-2-((4-(2-(2-((tert-butyldimethylsilyl)oxy)-2-methylpropyl)nicotinoyl)morpholin-3-yl)methoxy)-6-hydroxybenzaldehyde(600 mg, 1.14 mmol, 1.0 equiv), CH3CN (5.0 mL), and HCOOH (1.0 mL). Themixture was stirred for 1 h at 50° C. After cooling to room temperature,the reaction solution was directly purified by Prep-HPLC withconditions: Column, Ascentis Express C18, 50*3.0 mm, 2.7 um, MobilePhase A: Water/0.05% FA, Mobile Phase B: CH3CN, Flow rate: 1.5 mL/min,Gradient: 5% B to 100% B in 1.2 min, hold 0.6 min This resulted in(S)-2-hydroxy-6-((4-(2-(2-hydroxy-2-methylpropyl)nicotinoyl)morpholin-3-yl)methoxy)benzaldehyde.LCMS (ES, m/z): [M+H]⁺: 415.2. ¹H-NMR (300 MHz, DMSO-d₆, ppm): δ 11.75(br, 1H), 10.20 (s, 1H), 8.57 (s, 1H), 7.78-7.28 (m, 3H), 6.81-6.53 (m,2H), 5.19-4.35 (m, 4H), 4.11-3.88 (m, 1H), 3.71-3.35 (m, 4H), 3.15-2.59(m, 3H), 1.31-0.92 (m, 6H).

Example 36.2-hydroxy-6-({4-[2-(hydroxymethyl)benzoyl]thiomorpholin-3-yl}methoxy)benzaldehyde,Compound 40

Compound 40 was synthesized according to Scheme 36.

Step 1

Into a 500-mL 3-necked round-bottom flask, was placed2-hydroxymethylbenzoic acid (10.0 g, 65.7 mmol, 1.00 equiv), imidazole(8.95 g, 131 mmol, 2.00 equiv), and DCM (200 mL). To this solution wasadded TBDPS-Cl (21.6 g, 78.8 mmol, 1.20 equiv) dropwise at 0° C. Theresulting solution was stirred for 16 hr at 0-25° C. The reaction wasthen quenched by the addition of 50 mL of water. The resulting solutionwas extracted with 3×100 mL of DCM. The organic layer was dried andconcentrated. The residue was purified by silica gel columnchromatography with ethyl acetate/petroleum ether (1:50 to 1:1) aseluents. This resulted in2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoic acid. LCMS (ES) [M+1]⁺m/z: 391.2.

Step 2

To a solution of 2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoic acid(2.00 g, 5.12 mmol, 1.00 equiv) in DCM (20.0 mL) was added (COCl)₂ (1.30g, 10.2 mmol, 2.00 equiv) dropwise at 0° C. The resulting solution washeated to 40° C. for 5 h. The reaction was then concentrated to give aresidue. The residue was dissolved in THF (20.0 mL), and TEA (1.55 g,15.3 mmol, 3.00 equiv) was added. To this solution was addedthiomorpholin-3-ylmethanol (0.68 g, 5.12 mmol, 1.00 equiv) in portionsat 0° C. The resulting solution was stirred for 16 hr at 0-25° C. Thereaction was then quenched by the addition of 10 mL of water. Theresulting solution was extracted with 3×20 mL of ethyl acetate, driedover anhydrous sodium sulfate, and concentrated. The residue waspurified by silica gel column with ethyl acetate/petroleum ether (1:50to 1:5) as eluents. This resulted in[4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)thiomorpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 506.7.

Step 3

Into a 100-mL 3-necked round-bottom flask under N2 atmosphere, wasplaced[4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)thiomorpholin-3-yl]methanol(1.80 g, 3.55 mmol, 1.00 equiv), 2,6-dihydroxybenzaldehyde (0.74 g, 5.33mmol, 1.50 equiv), PPh₃ (1.40 g, 5.33 mmol, 1.50 equiv), and DCM (30.0mL). To this solution was added a solution of DBAD (1.23 g, 5.33 mmol,1.5.0 equiv) in DCM (3.0 mL) drop wise at 0° C. The resulting solutionwas stirred for 15 hr at 0-25° C. The resulting mixture wasconcentrated. The residue was applied onto a silica gel column withethyl acetate/petroleum ether (1:100 to 1:1). This resulted in2-[[4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)thiomorpholin-3-yl]methoxy]-6-hydro-xybenzaldehyde. LCMS (ES) [M+1]⁺ m/z: 626.2

Step 4

Into a 100-mL 3-necked round-bottom flask, was placed24[4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)thiomorpholin-3-yl]methoxyl hydroxybenzaldehyde (1.05g, 1.67 mmol, 1.00 equiv), THF (5.00 mL) and TBAF (0.33 mL, 0.330 mmol,0.20 equiv). The resulting solution was stirred for 2 hr at 0-25° C. Theresulting mixture was concentrated. The residue was purified by silicagel column with ethyl acetate/petroleum ether (50:1-1:1) as eluents.This resulted in2-hydroxy-6-({4-[2-(hydroxymethyl)benzoyl]thiomorpholin-3-yl}methoxy)benzaldehyde.LCMS (ES) [M+Na]⁺ m/z:410.1; ¹H NMR (300 MHz, DMSO-d₆) δ 12.00 (s, 1H),10.38 (s, 1H), 7.51-7.13 (m, 5H), 6.68-6.41 (m, 2H), 5.79-5.48 (m, 1H),5.01-4.30 (m, 6H), 3.84-2.31 (m, 5H).

Example 37.2-hydroxy-6-{[(3S)-4-[2-(hydroxymethyl)benzoyl]thiomorpholin-3-yl]methoxy}benzaldehydeand2-hydroxy-6-{[(3R)-4-[2-(hydroxymethyl)benzoyl]thiomorpholin-3-yl]methoxy}benzaldehyde

Compound 40 was purified by Chiral-Prep-HPLC (Conditions: Column LuxCellulose-4, 4.6*100 mm, 3 μm; mobile phase, A: n-Hexane B: Ethanol (35%B in 18 min); Flow rate: 30 mL/min; Detector, 220 nm) and was analyzedby analytical chiral HPLC (Conditions: instrument name: ShimadzuLC-20AD; Mobile Phase A: n-Hexane/DCM=5/1; Mobile Phase B: Ethanol;Column: CHIRALPAK IA-3, 50*4.6 mm, 3 um IA30CC-UL005). This resulted inEnantiomer 1 and Enantiomer 2 of Compound 40.

Compound 40, Enantiomer 1: Analytical chiral HPLC retention time=2.42min; LCMS (ES) [M+Na]⁺ m/z:410.1; ¹H NMR (300 MHz, DMSO-d₆) δ11.81-11.70 (m, 1H), 10.32-10.16 (m, 1H), 7.59-7.22 (m, 5H), 6.76 (d,J=8.3 Hz, 1H), 6.56 (d, J=8.4 Hz, 1H), 5.42-4.41 (m, 6H), 3.47-3.32 (m,1H), 3.32-2.90 (m, 2H), 2.63-2.51 (m, 2H), 2.50-2.40 (m, 1H).

Compound 40, Enantiomer 2: Analytical chiral HPLC retention time=4.50min. LCMS (ES) [M+Na]⁺ m/z:410.1; ¹H NMR (300 MHz, CDCl₃) δ 11.98-11.87(m, 1H), 10.36 (br, 1H), 7.54-7.34 (m, 4H), 7.26-7.15 (m, 1H), 6.59-6.52(m, 2H), 5.71-4.35 (m, 5H), 3.91-3.03 (m, 3H), 3.02-2.33 (m, 4H).

Example 38.2-hydroxy-6-{[(3R)-4-[2-(hydroxymethyl)benzoyl]thiomorpholin-3-yl]methoxy}benzaldehyde

Step 1

Into a 1-L round-bottom flask, was placed phthalide (25.0 g, 186.3 mmol,1.0 equiv), H₂O (250 mL) and NaOH (14.91 g, 372.762 mmol, 2 equiv). Theresulting solution was stirred for 3 h at 100° C. in an oil bath. Thereaction mixture was cooled to 0° C. Solids were precipitated out afterthe pH value of the solution was adjusted to 1 with HCl (12 mol/L). Thesolids product was collected by filtrate. This resulted in2-hydroxymethylbenzoic acid. LCMS (ES) [M+1]⁺ m/z: 153.1. ¹H NMR (300MHz, DMSO-d₆) δ 12.88 (br, 1H), 7.85 (dd, J=1.5, 7.8 Hz, 1H), 7.72 (dd,J=1.8, 7.8 Hz, 1H), 7.57 (td, J=1.5, 7.5 Hz, 1H), 7.34 (td, J=1.5, 7.8Hz, 1H), 4.84 (s, 2H).

Step 2

Into a 500-mL 3-necked round-bottom flask, was placed2-hydroxymethylbenzoic acid (15.0 g, 98.6 mmol, 1.0 equiv), DCM (200mL), and imidazole (10.0 g, 147.8 mmol, 1.5 equiv). After the reactionwas cooled to 0° C., TBDPSC1 (32.5 g, 118.3 mmol, 1.2 equiv) was addeddropwise with stirring at 0° C. The resulting solution was stirred for16 h at 25° C. The reaction was then quenched by the addition of 300 mLof water. The resulting solution was extracted with 3×250 mL of ethylacetate, dried over anhydrous sodium sulfate, and concentrated. Theresidue was purified by silica gel column chromatography with ethylacetate/petroleum ether (1:50 to 1:1) as eluents. This resulted in2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoic acid. LCMS (ES) [M+1]⁺m/z: 391.1. ¹H NMR (300 MHz, DMSO-d₆) δ 12.88 (s, 1H), 7.93 (td, J=1.8,7.8, Hz, 2H), 7.70-7.64 (m, 5H), 7.50-7.37 (m, 7H), 5.15 (s, 2H), 1.06(s, 9H).

Step 3

Into a 500-mL 3-necked round-bottom flask, was placed2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoic acid (15.0 g, 38.4 mmol,1.0 equiv), DCM (250 mL) and two drops of DMF. After the reaction wascooled to 0° C., (COCl)₂ (5.8 g, 46.1 mmol, 1.2 equiv) was addeddropwise with stirring at 0° C. The resulting solution was stirred for 5h at 40° C. The mixture was concentrated under vacuum. This resulted in2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl chloride, which was usedfor next step without further purification.

Step 4

To a solution of (3R)-thiomorpholin-3-ylmethanol (5.3 g, 40.3 mmol, 1.05equiv) and TEA (7.8 g, 76.7 mmol, 2.0 equiv) in THF (250 mL) was added2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl chloride (15.7 g, 38.3mmol, 1.0 equiv) in THF (50 mL) dropwise at 0° C. After the addition,the resulting solution was stirred for 5 h at 0-25° C. The reaction wasthen quenched by the addition of 50 mL of water. The resulting solutionwas extracted with 3×150 mL of ethyl acetate, dried over anhydroussodium sulfate, and concentrated. The residue was purified by silica gelcolumn chromatography with ethyl acetate/petroleum ether (1:50 to 1:5)as eluents. This resulted in[(3R)-4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)thiomorpholin-3-yl]methanol. LCMS (ES) [M+1]⁺ m/z: 506; ¹H NMR (300 MHz,DMSO-d₆) δ 7.65-7.63 (m, 5H), 7.62-7.27 (m, 9H), 4.84-4.53 (m, 4H),3.80-3.52 (m, 3H), 3.30-2.67 (m, 3H), 2.43-1.99 (m, 2H), 1.06 (s, 9H).

Step 5

Into a 2.5-L 3-necked round-bottom flask purged and maintained with aninert atmosphere of argon, was placed[(3R)-4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)thiomorpholin-3-yl]methanol(18.0 g, 35.5 mmol, 1.00equiv), 2,6-dihydroxybenzaldehyde (5.4 g, 39.1mmol, 1.1 equiv), DCM (900.00 mL) and PPh₃ (14.0 g, 53.3 mmol, 1.5equiv). This was followed by the addition of DBAD (9.8 g, 42.7 mmol, 1.2equiv) in DCM (100 mL) dropwise with stirring at 0° C. The resultingsolution was stirred for 15 hr at 0-25° C. The resulting mixture wasconcentrated. The residue was purified by silica gel columnchromatography with ethyl acetate/petroleum ether (1:100 to 1:1) aseluents. This resulted in2-[[(3R)-4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z: 626.2; ¹H NMR (300 MHz, DMSO-d₆) δ 11.71 (s, 1H),10.19 (s, 1H), 7.61-7.41 (m, 16H), 6.55 (d, J=8.4 Hz, 1H), 5.23-5.19 (m,1H), 4.69-4.21 (m, 5H), 3.41-3.37 (m, 2H), 3.07-2.85 (m, 2H), 2.16-1.99(m, 1H), 1.06 (s, 9H).

Step 6

Into a 500-mL 3-necked round-bottom flask, was placed2-[[(3R)-4-(2-[[(tert-butyldiphenylsilyl)oxy]methyl]benzoyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(14.0 g, 22.3 mmol, 1.0 equiv) and THF (140 mL). To this solution wasadded a solution of TBAF (4.5 mL, 4.50 mmol, 0.20 equiv, 1 M in THF)dropwise with stirring at 0° C. The resulting solution was stirred for 3hr at 0-25° C. The resulting mixture was concentrated. The residue wasapplied onto a silica gel column with ethyl acetate/petroleum ether(1:50 to 1:1) to give crude product. The crude product was purified byFlash-Prep-HPLC with the following conditions (IntelFlash-1): Column,C18 silica gel; mobile phase, MeCN/H₂O=1:9 increasing to MeCN/H₂O=1:1within 15; Detector, 220. This resulted in2-hydroxy-6-{[(3R)-4-[2-(hydroxymethyl)benzoyl]thiomorpholin-3-yl]methoxy}benzaldehyde,which was subjected to chiral analytical HPLC analysis with thefollowing conditions: Instrument Name: Shimadzu LC-20AD; Mobile Phase A:n-Hexane/DCM=5/1; Mobile Phase B: Ethanol; Column: CHIRALPAK IA-3,50*4.6 mm, 3 um IA30CC-UL005. Analytical Chiral HPLC retention time:4.540 min. LCMS (ES, m/z): [M+Na]⁺: 410.1; ¹H NMR (300 MHz, DMSO-d₆) δ11.81-11.70 (m, 1H), 10.32-10.10 (m, 1H), 7.59-7.22 (m, 5H), 6.77-6.55(m, 2H), 5.42-4.08 (m, 6H), 3.42-3.37 (m, 1H), 3.21-2.90 (m, 2H),2.71-2.95 (m, 2H), 2.44-2.40 (m, 1H).

Based on the product of Scheme 38, it was determined that Compound 40,Enantiomer 2 corresponds to2-hydroxy-6-{[(3R)-4-[2-(hydroxymethyl)benzoyl]thiomorpholin-3-yl]methoxy}benzaldehyde.

Example 39.2-{[(2S)-1-{2-[(1R)-1,2-dihydroxyethyl]benzoyl}piperidin-2-yl]methoxy}-6-hydroxybenzaldehydeand2-{[(2S)-1-{2-[(1S)-1,2-dihydroxyethyl]benzoyl}piperidin-2-yl]methoxy}-6-hydroxybenzaldehyde

Step 1

Into a 500-mL 3-necked round-bottom flask, was placed2-bromobenzaldehyde (10.0 g, 54.05 mmol, 1.0 equiv),methyltriphenyl-lambda5-phosphane hydrobromide (23.20 g, 64.58 mmol, 1.2equiv), and DMF (100 mL). This was followed by the addition of NaH (60%in mineral oil) (9.67 g, 241.69 mmol, 4.5 equiv) carefully at 0° C. byfour batches. The mixture was stirred overnight at room temperature. Thereaction was then quenched by the addition of water/ice (100 mL),extracted with 3×100 mL of ethyl acetate. The combined organic phase waswashed with brine (80 mLx3) and dried over anhydrous sodium sulfate. Themixture was filtered, and the filtrate was concentrated under reducedpressure. The residue was purified by silica gel column chromatographywith PE (100%) as eluents. This resulted in 1-bromo-2-vinylbenzene.GCMS:182.

Step 2

Into a 250-mL round-bottom flask, was placed 1-bromo-2-vinylbenzene(8.50 g, 46.43 mmol, 1.0 equiv), acetone (130 mL), H₂O (13 mL), NMO(5.43 g, 46.35 mmol, 1.0 equiv), and K₂OsO₄.2H₂O (730 mg, 2.32 mmol,0.05 equiv). The mixture was stirred overnight at room temperature. Themixture was concentrated to remove the solvent, and the residue waspurified by silica gel column chromatography with THF/PE (15%) aseluents. This resulted in −(2-bromophenyl)ethane-1,2-diol. LCMS (ES)[M+1]⁺ m/z: 217.

Step 3

Into a 250-mL round-bottom flask, was placed1-(2-bromophenyl)ethane-1,2-diol (5.10 g, 23.50 mmol, 1.0 equiv),2,2-dimethoxypropane (4.17 g, 40.04 mmol, 1.7 equiv), TsOH (812 mg, 4.72mmol, 0.20 equiv), and DMF (75 mL). The reaction solution was stirredfor 5 h at room temperature. The reaction was then quenched by theaddition of water (100 mL) and extracted with 3×100 mL of ethyl acetate.The combined organic phase was washed with brine (100 mL*3) and driedover anhydrous sodium sulfate. The mixture was filtered, and thefiltrate was concentrated under reduced pressure. The residue waspurified by silica gel column chromatography with PE (100%) as eluents.This resulted in 4-(2-bromophenyl)-2,2-dimethyl-1,3-dioxolane. GCMS:256.

Step 4

Into a 100-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed4-(2-bromophenyl)-2,2-dimethyl-1,3-dioxolane (2.50 g, 9.72 mmol, 1.0equiv), THF (50 mL). This was followed by the addition of n-BuLi (2.5 Min THF) (4.68 mL, 11.68 mmol, 1.2 equiv) at -78° C. The reactionsolution was stirred for 30 min at −78° C. To this ethyl chloroformate(2.11 g, 19.44 mmol, 2.0 equiv) was added at −78° C. The resultingsolution was stirred for additional 1 h at room temperature. Thereaction was then quenched by the addition of NH₄Cl (aq) (60 mL) andextracted with 3×50 mL of ethyl acetate. The combined organic phase wasdried over anhydrous sodium sulfate and filtered, and the filtrate wasconcentrated under reduced pressure. The residue was purified by silicagel column chromatography with ethyl acetate/petroleum ether(1:10) aseluents. This resulted in ethyl2-(2,2-dimethyl-1,3-dioxolan-4-yl)benzoate. GCMS: 250.

Step 5

Into a 100-mL round-bottom flask, was placed ethyl2-(2,2-dimethyl-1,3-dioxolan-4-yl)benzoate (1.60 g, 6.39 mmol, 1.0equiv), EtOH (10.0 mL), H₂O (50.0 mL), and LiOH H₂O (538 mg, 12.82 mmol,2.0 equiv). The reaction solution was stirred overnight at roomtemperature. The mixture was concentrated to remove the solvent, and thepH value of the residue was adjusted to 4 with 2N HCl. The solid wascollected by filtration and dried under infrared lamp. This resulted in2-(2,2-dimethyl-1,3-dioxolan-4-yl)benzoic acid. LCMS (ES) m/z: 221.

Step 6

Into a 50-mL 3-necked round-bottom flask, was placed2-(2,2-dimethyl-1,3-dioxolan-4-yl)benzoic acid (865 mg, 3.89 mmol, 1.0equiv), (2S)-piperidin-2-ylmethanol (537 mg, 4.66 mmol, 1.2 equiv), DMF(20 mL), and DIEA (1.0 g, 7.74 mmol, 2.0 equiv). This was followed bythe addition of HATU (1.78 g, 4.68 mmol, 1.2 equiv) at 0° C. The mixturewas stirred for 2 h at room temperature. The reaction was then quenchedby the addition of water (30 mL) and extracted with 3×20 mL of ethylacetate. The combined organic phase was dried over anhydrous sodiumsulfate and filtered, and the filtrate was concentrated in vacuum. Theresidue was purified by silica gel column chromatography with ethylacetate/petroleum ether (1/3) as eluents. This resulted in(2-(2,2-dimethyl-1,3-dioxolan-4-yephenyl)((S)-2-(hydroxymethyl)piperidin-1-yl)methanone.LCMS (ES) [M+1]⁺ m/z:320.

Step 7 and Step 8

Into a 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed(2-(2,2-dimethyl-1,3-dioxolan-4-yl)phenyl)((S)-2-(hydroxymethyl)piperidin-1-yl)methanone(900 mg, 2.82 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (467 mg, 3.38mmol, 1.2 equiv), PPh3 (887 mg, 3.38 mmol, 1.20 equiv), and THF (60 mL).This was followed by the addition of DIAD (684 mg, 3.38 mmol, 1.2 equiv)at 0° C. After addition, the reaction solution was stirred overnight atroom temperature. The mixture was concentrated to remove the solvent,and the residue was purified by silica gel column chromatography withethyl acetate/petroleum ether (1/1) as eluents.

The collected racemate product was separated by Chiral-Prep-HPLC withthe following conditions: Mobile phase: A: n-Hexane, B: Ethanol, Flowrate: 20 mL/min, Column: CHIRALPAK IC-3, 4.6*50 mm, 3pm, Gradient: 30% Bin 18 min, 220 nm.

The separated enantiomers were subjected to analytical chiral HPLCanalysis (Instrument Name: Shimadzu LC-20AD; Mobile Phase A: n-Hexane;Mobile Phase B: Ethanol; Column: CHIRALPAK IC-3, 50*4.6 mm, 3umIC30CC-SC002). This resulted in Compound 39h, Diastereomer 1(chiral-HPLC analysis conditions: Rt=2.03 min) and Compound 39h,Diastereomer 2 (chiral-HPLC analysis conditions: Rt=2.89 min). LCMS (ES)[M+1]⁺ m/z: 440

Step 9a

Into a 25-mL vial, was placed Compound 39h, Diastereomer 1 (288 mg, 0.66mmol, 1.0 equiv), CH₃CN (8.0 mL), and Yb(OTf)₃ (203 mg, 0.33 mmol, 0.50equiv). The mixture was stirred for 2 h at room temperature. Thereaction solution was directly purified by Prep-HPLC with the followingconditions (SHIMADZU (HPLC-01): Column, XBridge C18 OBD Prep Column, 10μm, 19 mm×250 mm, mobile phase, Water (0.1% FA) and CH3CN (5% Phase B upto 50% in 12 min), Detector, UV 254 nm. This resulted in Compound 34,Diastereomer 1. LCMS (ES, m/z): [M+H]⁺: 400. ¹H-NMR (300 MHz, DMSO-d₆,ppm): δ 11.83-11.73 (m, 1H), 10.30-10.19 (m, 1H), 7.57-7.21 (m, 5H),6.79-6.53 (m, 2H), 5.25-4.56 (m, 6H), 3.47-2.88 (m, 4H), 1.93-1.37 (m,6H).

Step 9b

Into a 25-mL round-bottom flask, was placed Compound 39h, Diastereomer 2(307 mg, 0.70 mmol, 1.0 equiv), CH₃CN (8.0 mL), Yb(OTf)₃ (203 mg, 0.35mmol, 0.50 equiv). The reaction solution was stirred for 2 h at roomtemperature. The reaction solution was directly purified by Prep-HPLCwith the following conditions (SHIMADZU (HPLC-01): Column, XBridge C18OBD Prep Column, 10 μm, 19 mm×250 mm, mobile phase, Water (0.1% FA) andCH₃CN (5% Phase B up to 50% in 12 min), Detector, UV 254 nm. Compound34, Diastereomer 2 was obtained. LCMS (ES, m/z): [M+H]⁺: 400. ¹H-NMR(300 MHz, DMSO-d₆, ppm): δ 11.83-11.73 (m, 1H), 10.33-10.10 (m, 1H),7.59-7.20 (m, 5H), 6.79-6.53 (m, 2H), 5.25-4.56 (m, 6H), 3.47-2.88 (m,4H), 1.94-1.37 (m, 6H).

Example 40.2-hydroxy-6-{[(3S)-4-{2-[(1S)-1-hydroxyethyl]pyridine-3-carbonyl}morpholin-3-yl]methoxy}benzaldehydeand2-hydroxy-6-{[(3S)-4-{2-[(1R)-1-hydroxyethyl]pyridine-3-carbonyl}morpholin-3-yl]methoxy}benzaldehyde

Compound 41, Diastereomer 1 and Compound 41, Diastereomer 2 weresynthesized according to Scheme 40.

Step 1

Into a 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed a mixture of3-bromopyridine-2-carbaldehyde (10.0 g, 53.7 mmol, 1.00 equiv),tetrahydrofuran (150 mL), and bromo(methyl)magnesium (35.8 mL, 2.0equiv) was dropwised at −78° C. The solution was stirred for 30 minutesat —78° C. and then allowed to room temperature over 30 minutes. Thereaction was then quenched by the addition of 100 mL. The resultingsolution was extracted with 3×100 mL of ethyl acetate. The resultingmixture was washed with 1×100 mL of brine. The mixture was dried overanhydrous sodium sulfate and concentrated. This resulted in1-(3-bromopyridin-2-yl)ethanol. LCMS (ES) [M+1]⁺ m/z: 202.

Step 2

Into a 250-mL round-bottom flask, was placed a mixture of1-(3-bromopyridin-2-yl)ethanol (8.00 g, 39.5 mmol, 1.00 equiv), DMF(80.0 mL), tert-butyl(chloro)diphenylsilane (16.3 g, 59.3 mmol, 1.50equiv), and imidazole (5.39 g, 79.1 mmol, 2.00 equiv). The resultingsolution was stirred for 16 hours at room temperature. The reaction wasthen quenched by the addition of 500 mL of water. The resulting solutionwas extracted with 3×150 mL of ethyl acetate. The resulting mixture waswashed with 1×150 mL of brine. The mixture was dried over anhydroussodium sulfate and concentrated. The residue was applied onto a silicagel column with ethyl acetate/petroleum ether (1/9). This resulted in3-bromo-2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine. LCMS (ES)[M+1]⁺ m/z: 440.1.

Step 3

Into a 1000 mL pressure tank reactor, was placed a mixture of3-bromo-2[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine (14.0 g, 31.7mmol, 1.00 equiv), methanol (200 mL), Et₃N (6.43 g, 63.5 mmol, 2.00equiv), and Pd(dppf)Cl₂ (2.33 g, 3.18 mmol, 0.10 equiv). The reactor wasevacuated and flushed three times with nitrogen, followed by flushingwith 30 atm CO. The resulting solution was stirred for 16 hours at 110°C. The resulting mixture was concentrated. The residue was purified bysilica gel column chromatography with ethyl acetate/petroleum ether(2/23) as eluent. This resulted in methyl2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carboxylate. LCMS(ES) [M+1]⁺ m/z: 420.2.

Step 4

Into a 250-mL round-bottom flask, was placed a mixture of methyl2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carboxylate (10.0 g,23.8 mmol, 1.00 equiv), MeOH (100 mL), and LiOH (1.71 g, 71.4 mmol, 3.00equiv). The resulting solution was stirred for 3 hours at 50 degrees C.The resulting mixture was concentrated. The resulting solution wasdiluted with 100 mL of H₂O. The pH value of the solution was adjusted to3 with HCl (2 mol/L). The solids were collected by filtration. Thisresulted in2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carboxylic acid.LCMS (ES) [M+1]⁺ m/z: 406.2.

Step 5

Into a 250-mL round-bottom flask, was placed a mixture of2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carboxylic acid(7.00 g, 17.6 mmol, 1.00 equiv), DCM (100 mL),(3R)-morpholin-3-ylmethanol hydrochloride (3.45 g, 22.4 mmol, 1.30equiv), DIEA (6.69 g, 51.7 mmol, 3.0 equiv), and HATU (7.88 g, 20.7mmol, 1.2 equiv). The resulting solution was stirred for 3 hours at roomtemperature. The resulting mixture was concentrated. The residue waspurified by silica gel column chromatography with ethylacetate/petroleum ether (3/2) as eluent. This resulted in[(3R)-4-(2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carbonyl)morpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 505.3.

Step 6

Into a 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen, was placed a mixture of[(3R)-4-[2-[(1S)-1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carbonyl]morpholin-3-yl]methanol(2.0 g, 3.96 mmol, 1.00 equiv), DCM (100 mL), 2,6-dihydroxybenzaldehyde(0.71 g, 5.15 mmol, 1.30 equiv), and PPh₃ (1.56 g, 5.94 mmol, 1.50equiv). DBAD (1.00 g, 4.35 mmol, 1.10 equiv) was added dropwise at 0° C.The resulting solution was stirred for 16 hours at room temperature. Theresulting mixture was concentrated. The residue was purified by silicagel column chromatography with ethyl acetate/petroleum ether (1/1) aseluents.

This resulted in Compound 40 g, Diastereomer 1 (LCMS, Retention time:1.896 min). and Compound 40 g, Diastereomer 2 (LCMS retention time:1.872 min, (ES) [M+1]⁺ m/z: 625.2). LCMS analysis conditions:Instrument: Shimadzu LC2020; Column: Kinetex XB-C18, 50*3.0 mm, Particlesize 2.6 um; Mobile phase A: Water/0.05% TFA; Mobile phase B:Acetonitrile/0.05% TFA; Gradient: 5-100% B in 3 min

Step 7A

Into a 20-mL vial, was placed a solution of Compound 40 g, Diastereomer1 (400 mg, 0.640 mmol, 1.00 equiv), THF (4.00 mL), and TBAF/THF (3.21mL, 3.20 mmol, 5.00 equiv). The resulting solution was stirred for 3hours at 45 degrees C. The residue was applied onto a silica gel columnwith ethyl acetate/petroleum ether (99/1-1/9).The crude reaction mixturewas filtered and subjected to reverse phase preparative HPLC (XB-C18,50-250 mm,10 mM; gradient elution of 10% MeCN in water to 45% MeCN inwater over a 20 min period, where both solvents contain 0.1% formicacid), and the product was analyzed by analytical chiral HPLC(Instrument: Shimadzu LC-20AD; Mobile Phase A: n-Hexane(0.1% TFA);Mobile Phase B:EtOH/MeOH =1/1; Conc. of Phase B: 20.0%; Column:CHIRALPAK IC-3, 50*4.6 mm, 3 um IC30CC-SC002; Column ID: AY3OCC-SK001;Flow Rate: 1.000 mL/min). This resulted in Compound 41, Diastereomer 1.Analytical chiral HPLC Retention time=5.801 mM. LCMS (ES) [M+1]⁺ m/z:387.1. ¹H NMR (300 MHz, DMSO-d₆) δ 11.84-11.69 (m, 1H), 10.35-10.14 (m,1H), 8.58-8.54 (m, 1H), 7.69-7.32 (m, 3H), 6.75-6.54 (m, 2H), 5.33-4.21(m, 5H), 4.20-3.63 (m, 4H), 3.60-3.35 (m, 1H), 3.23-2.91 (m, 1H),1.51-1.25 (m ,3H).

Step 7B

Into a 20-mL vial, was placed a solution of Compound 40 g, Diastereomer2 (500 mg, 0.800 mmol, 1.00 equiv), THF (5.00 mL), and TBAF (4.01 mL,4.00 mmol, 5.00 equiv). The resulting solution was stirred for 3 hoursat 45 degrees C. The residue was applied onto a silica gel column withethyl acetate/petroleum ether (99/11/9). The crude reaction mixture wasfiltered and subjected to reverse phase preparative HPLC (XB-C18, 50-250mm,10 mM; gradient elution of 10% MeCN in water to 45% MeCN in waterover a 20 mM period, where both solvents contain 0.1% formic acid), andthe product was analyzed by analytical chiral HPLC (Instrument: ShimadzuLC-20AD; Mobile Phase A: n-Hexane(0.1% TFA); Mobile PhaseB:EtOH/MeOH=1/1; Conc. of Phase B: 20.0%; Column: CHIRALPAK IC-3, 50*4.6mm, 3 um IC30CC-SC002; Column ID: AY3OCC-SK001; Flow Rate: 1.000mL/min). This resulted in Compound 41, Diastereomer 2. Analytical chiralHPLC Retention time=4.128 mM. LCMS (ES) [M+1]⁺ m/z: 387.1. ¹H NMR (300MHz, DMSO-d6) 6 11.84-11.20 (br, 1H), 10.38-10.15 (m, 1H), 8.58-8.53 (m,1H), 7.70-7.30 (m, 3H), 6.77-6.51 (m, 2H), 5.33-4.75 (m, 3H), 4.55-3.63(m, 7H), 3.21-3.02 (m, 1H), 1.51-1.10 (m, 3H).

Example 41.2-hydroxy-6-{[(3S)-4-{2-[(2S)-2-hydroxypropyl]pyridine-3-carbonyl}morpholin-3-yl]methoxy}benzaldehydeand2-hydroxy-6-{[(35)-4-{2-[(2R)-2-hydroxypropyl]pyridine-3-carbonyl}morpholin-3-yl]methoxy}benzaldehyde

Compound 42, Diastereomer 1 and Compound 42, Diastereomer 2 weresynthesized according to Scheme 41.

Step 1

Into a 1000-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of nitrogen was placed 3-bromo-2-methylpyridine (25 g,145.33 mmol, 1.00 equiv) and THF (500.00 mL). This was followed by theaddition of LDA (87.20 mL, 174.40 mmol, 1.20 equiv) dropwise withstirring at -78° C. The resulting solution was stirred for 1 h at −78°C. To this mixture was added acetaldehyde (7.04 g, 159.81 mmol, 1.10equiv) dropwise with stirring at −78° C. The resulting solution wasstirred for 1 h at −78° C. The reaction was then quenched by theaddition of 300 mL of saturated NH₄Cl solution. The resulting mixturewas extracted with 3×300 mL of ethyl acetate, and the organic layerswere combined, dried over anhydrous sodium sulfate, and concentrated.The residue was purified by silica gel column chromatography usingTHF/PE (20%) as eluent to yield 1-(3-bromopyridin-2-yl)propan-2-ol. LCMS(ES) [M+1]⁺ m/z: 216.

Step 2

Into a 1000-mL round-bottom flask, was placed1-(3-bromopyridin-2-yl)propan-2-ol (15.00 g, 69.42 mmol, 1.00 equiv),imidazole (9.45 g, 138.81 mmol, 2.00 equiv), DMF (300.00 mL), DMAP (0.85g, 6.94 mmol, 0.1 equiv) and TBDPSC1 (22.90 g, 83.30 mmol, 1.20 equiv).The resulting solution was stirred for overnight at 60° C. The reactionmixture was cooled to room temperature. The reaction was then quenchedby the addition of 300 mL of water. The resulting solution was extractedwith 3×300 mL of ethyl acetate, and the organic layers were combined,dried over anhydrous sodium sulfate, and concentrated. The residue waspurified by silica gel column chromatography using THF/PE (5%) to yield3-bromo-2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine. LCMS (ES)[M+1]⁺ m/z: 454.

Step 3

Into a 2000-mL pressure tank reactor was placed3-bromo-2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine (25.00 g,55.00 mmol, 1.00 equiv), MeOH (800.00 mL), TEA (11.13 g, 110.01 mmol,2.00 equiv), and Pd(dppf)Cl₂ (4.02 g, 5.49 mmol, 0.10 equiv). Thereactor was evacuated and flushed three times with nitrogen, followed byflushing with 30 atm CO. The resulting solution was stirred forovernight at 110° C. The reaction mixture was cooled to roomtemperature. The resulting mixture was concentrated. The residue waspurified with silica gel column chromatography using THF/PE (7%) toyield methyl2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carboxylate. LCMS(ES) [M+1]⁺ m/z: 434.

Step 4

Into a 1000-mL round-bottom flask, was placed methyl2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carboxylate (20.00g, 46.12 mmol, 1.00 equiv), MeOH (400 mL), H₂O (200 mL), and LiOH H₂O(3.87 g, 92.22 mmol, 2.00 equiv). The resulting solution was stirred for4 h at 50° C. The reaction mixture was cooled to room temperature. Theresulting mixture was concentrated. The resulting solution was extractedwith 200 mL of ethyl acetate, and the aqueous layers combined. The pHvalue of the solution was adjusted to 4-5 with HCl (1 mol/L). Theresulting precipitates were collected by filtration and dried underinfrared light. This resulted in2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carboxylic acid.LCMS (ES) [M+1]⁺ m/z: 420.

Step 5

Into a 250-mL 3-necked round-bottom flask, was placed2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carboxylic acid(4.00 g, 9.53 mmol, 1.00 equiv), (3R)-morpholin-3-ylmethanolhydrochloride (1.76 g, 11.46 mmol, 1.20 equiv), DCM (100.00 mL), andDIEA (3.70 g, 28.59 mmol, 3.00 equiv). This was followed by the additionof HATU (4.35 g, 11.44 mmol, 1.20 equiv) in portions at 0° C. Theresulting solution was stirred for 3 h at room temperature. The reactionwas then quenched by the addition of 100 mL of water. The resultingsolution was extracted with 3×100 mL of dichloromethane, and the organiclayers were combined, dried over anhydrous sodium sulfate, andconcentrated. The residue was purified with silica gel columnchromatography using THF/PE (25%) as eluent to yield[(3R)-4-(2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carbonyl)morpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 519.

Step 6

Into a 250-mL 3-necked round-bottom flask, was placed2,6-dihydroxybenzaldehyde (0.96 g, 6.94 mmol, 1.20 equiv),[(3R)-4-(2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carbonyl)morpholin-3-yl]methanol(3.00 g, 5.78 mmol, 1.00 equiv), PPh₃ (1.82 g, 6.94 mmol, 1.20 equiv),and DCM (100.00 mL). This was followed by the addition of DIAD (1.40 g,6.92 mmol, 1.20 equiv) dropwise with stirring at 0° C. The resultingsolution was stirred for overnight at room temperature. The resultingmixture was concentrated. The residue was purified with silica gelcolumn using THF/PE (30%) as eluent to give crude product. The crudeproduct was purified by Prep-HPLC with the following conditions: ColumnWelch XB-C18 50*250 mm, 10 um, mobile phase, Water (0.1% TFA) and ACN(50% in 100 min); Detector, 254. This resulted in Compound 41 g,Diastereomer 1 (Retention time=70 min) and Compound 41g, Diastereomer 2(Retention time=90 min). LCMS (ES) [M+1]⁺ m/z: 639.

Step 7A

Into a 40-mL vial, was placed Compound 41g, Diastereomer 1 (1.2 g, 1.88mmol, 1.00 equiv), THF (9.00 mL), and TBAF/THF (9.39 mL, 9.39 mmol, 5.00equiv). The resulting solution was stirred for 5 h at 45° C. Thereaction mixture was cooled to room temperature. The crude product waspurified by Prep-HPLC with the following conditions: Column, XBridgePrep C18 OBD Column, 19 cm, 150 mm, 5 um; mobile phase, Water (0.1%HCOOH) and ACN (5% to 55% in 15 min); Detector, 254. This resulted inCompound 42, Diastereomer 1. The final compound was analyzed with ChiralHPLC with these conditions: Instrument: SHIMADZU LC-20AT; Mobile PhaseA: n-Hexane; Mobile Phase B: Mobile Phase B; Conc. of Phase B: 50.0%,Flow Rate Column: 1.000 mL/min: CHIRALPAK AY-3, 4.6*50 mm, 3pm; ColumnID: AY3OCC-SK001; Retention time=3.35 min. LCMS: (ES, m/z): [M+H]⁺ :401. ¹H-NMR (300 MHz, DMSO-d₆, ppm): δ 11.80-11.67 (m, 1H), 10.34-10.23(m, 1H), 8.58 (dd, J=4.9, 1.7 Hz, 1H), 7.75 (d, J=7.9 Hz, 1H), 7.57 (t,J=8.4 Hz, 1H), 7.33 (d, J=5.7 Hz, 1H), 6.75 (d, J=8.1 Hz, 1H), 6.55 (dd,J=8.5, 4.9 Hz, 1H), 5.04-4.89 (m, 1H), 4.49-4.29 (m, 4H), 4.09 (d,J=12.1 Hz, 1H), 3.99-3.63 (m, 3H), 3.57-3.07 (m, 3H), 2.94-2.60 (m, 1H),1.19-0.81 (m, 3H).

Step 7B

Into a 40-mL vial, was placed Compound 41g, Diastereomer 2 (1.20 g, 1.88mmol, 1.00 equiv), THF (9.00 mL), and TBAF (9.39 mL, 9.39 mmol, 5.00equiv). The resulting solution was stirred for 5 h at 45° C. Thereaction mixture was cooled to room temperature. The crude product waspurified by Prep-HPLC with the following conditions: Column, XBridgePrep C18 OBD Column, 19 cm, 150 mm, 5 um; mobile phase, Water (0.1%HCOOH) and ACN (5% to 55% in 15 min); Detector, 254. This resulted inCompound 42, Diastereomer 2. The final compound was analyzed with ChiralHPLC with these conditions: Instrument: SHIMADZU LC-20AT; Mobile PhaseA: n-Hexane; Mobile Phase B: Mobile Phase B; Conc. of Phase B: 50.0%;Flow Rate Column 1 000 mL/min: CHIRALPAK AY-3, 4.6*50 mm, 3 μm; ColumnID: AY3OCC-SK001; Retention time=1.91 min. LCMS: (ES, m/z): [M+H]⁺: 401.¹H-NMR: (300 MHz, DMSO-d₆, ppm): δ 11.82-11.69 (m, 1H), 10.33-10.23 (m,1H), 8.58 (dd, J=4.9, 1.8 Hz, 1H), 7.84-7.26 (m, 3H), 6.76 (d, J=8.3 Hz,1H), 6.56 (d, J=8.4 Hz, 1H), 4.95 (s, 1H), 4.45-4.15 (m, 4H), 4.09 -3.61(m, 4H), 3.46-3.12 (m, 3H), 2.95-2.66 (m, 1H), 1.20-0.83 (m, 3H).

Example 42.2-hydroxy-6-{[(3R)-4-{2-[(1S)-1-hydroxyethyl]pyridine-3-carbonyl}thiomorpholin-3-yl]methoxy}benzaldehydeand2-hydroxy-6-{[(3R)-4-{2-[(1R)-1-hydroxyethyl]pyridine-3-carbonyl}thiomorpholin-3-yl]methoxy}benzaldehyde

Compound 43, Diastereomer 1 and Compound 43, Diastereomer 2 weresynthesized according to Scheme 42.

Step 1

To a solution of2[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carboxylic acid (2.0g, 4.93 mmol, 1.0 equiv)) in DMF (20.0 mL) was added DIPEA (1.27 g, 9.8mmol, 2.0 equiv) and HATU (2.25 g, 5.9 mmol, 1.2 equiv) at 0° C. Afterthe reaction mixture was stirred at 0° C. for 20 min,(3R)-thiomorpholin-3-ylmethanol (720 mg, 5.42 mmol, 1.10 equiv) wasadded in portions. The resulting solution was stirred for 2 h at 25° C.The reaction was then quenched by the addition of 50 mL of water. Theresulting solution was extracted with 3×80 mL of ethyl acetate. Thecombined organic layer was dried over anhydrous sodium sulfate andconcentrated under vacuum. The residue was purified by silica gel columnchromatography using ethyl acetate/petroleum ether (1:100 to 1:1) aseluent. This resulted in[(3R)-4-(2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 521.2; ¹H-NMR: (300 MHz, DMSO-d6, ppm): δ 8.75 (d,J=5.4 Hz, 1H), 7.96 (s, 1H), 7.71-7.26 (m, 11H), 4.98-4.44 (m, 3H),4.07-3.54 (m, 2H), 3.12-2.97 (m, 1H), 2.91-2.84 (m, 1H), 2.74-2.70 (m,1H), 2.38-2.33 (m, 1H), 1.79-1.69 (m, 1H), 1.59-1.10 (m, 3H), 0.92 (s,9H).

Step 2

A solution of[(3R)-4-(2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol(1.3 g, 2.5 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (380 mg, 2.72mmol, 1.1 equiv) and PPh₃ (980 mg, 3.75 mmol, 1.5 equiv) in DCM (200 mL)was cooled to 0° C. under Argon atmosphere. A solution of DBAD (690 mg,3.0 mmol, 1.2 equiv) in DCM (30 mL) was added dropwise. After theaddition, the resulting solution was stirred for 16 h at 0-25° C. Thereaction was concentrated under vacuum. The residue was purified bysilica gel column using ethyl acetate/petroleum ether (1:100 to 1:5) aseluent. This resulted in2-[[(3R)-4-(2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carbonyethiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1]⁺ m/z: 641.2; ¹H-NMR (300 MHz, CDCl3, ppm): δ 11.96 (s,1H), 10.25 (br, 1H), 8.89-8.78 (m, 1H), 7.81-7.19 (m, 13H), 6.63-6.28(m, 2H), 5.21-4.89 (m, 2H), 4.45-4.13 (m, 2H), 3.71-3.66 (m, 1H),3.18-2.92 (m, 2H), 2.75-2.35 (m, 3H), 1.74-1.50 (m, 3H), 0.92 (s, 9H).

Step 3

Into a 100-mL 3-necked round-bottom flask, was placed2-[[(3R)-4-(2-[1-[(tert-butyldiphenylsilyl)oxy]ethyl]pyridine-3-carbonyethiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(2.0 g, 3.12 mmol, 1.0 equiv) and THF (10 mL). After the reaction wascooled to 0° C., TBAF (1.63 g, 6.24 mmol, 2.0 equiv) was added inportions. The resulting solution was stirred for 5 h at 45° C. Theresulting solution was quenched with NH₄Cl (20 mL, 2N) and extractedwith ethyl acetate (50 mL×3); the organic layers were combined andconcentrated. The residue was purified by silica gel column eluted withPE/EA=100:1 to 1:1 to give the racemate product, which was purified byPreparative Chiral-HPLC with the following conditions: ColumnLuxAmylose-1, 50*250 mm, 10 um; Mobile phase: A:n-Hexane B:Ethanol; Flowrate: 90 mL/min; Gradient:50% B in 50 min; 220 nm. The isolateddiastereomers were analyzed by analytical HPLC using the followingconditions: Instrument: SHIMADZU LC-20AT; Mobile Phase A: n-Hexane;Mobile Phase B: Ethanol; Conc. of Phase B: 50.0%; Flow Rate: 1.000mL/min; Column: Lux Amylose-1, 4.6*100 mm, 3 μm; Column ID: H18-344853.This resulted in Compound 43, Diastereomer 1 and Compound 43,Diastereomer 2.

Data for Compound 43, Diastereomer 1: Chiral HPLC retention time 8.31min; LCMS (ES, m/z): [M+H]⁺: 403.1; ¹H-NMR: (300 MHz, DMSO-d6, ppm): δ11.85 (br, 1H), 10.35-10.16 (m, 1H), 8.57-8.53 (m, 1H), 7.75-7.32 (m,3H), 6.77-6.55 (m, 2H), 5.42-5.27 (m, 2H), 4.88-4.03 (m, 3H), 3.47-3.44(m, 2H) , 3.21-2.73 (m, 3H), 2.50-2.44 (m, 1H), 1.43-1.34 (m, 3H).

Data for Compound 43, Diastereomer 2: Chiral HPLC retention time 5.30min; LCMS (ES, m/z): [M+H]⁺: 403.1; ¹H-NMR: (300 MHz, DMSO-d6, ppm): δ11.79 (br, 1H), 10.32-10.16 (m, 1H), 8.60-8.53 (m, 1H), 7.77-7.28 (m,3H), 6.77-6.55 (m, 2H), 5.43-5.5.33 (m, 2H), 4.88-4.06 (m, 3H),3.50-3.34 (m, 2H) , 3.15-2.36 (m, 4H), 1.46-1.34 (m, 3H).

Example 43.2-hydroxy-6-{[(3R)-4-{2-[(2S)-2-hydroxypropyl]pyridine-3-carbonyl}thiomorpholin-3-yl]methoxy}benzaldehydeand2-hydroxy-6-{[(3R)-4-{2-[(2R)-2-hydroxypropyl]pyridine-3-carbonyl}thiomorpholin-3-yl]methoxy}benzaldehyde

Compound 44, Diastereomer 1 and Compound 44, Diastereomer 2 weresynthesized according to Scheme 43.

Step 1

To a solution of2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carboxylic acid(2.0 g, 4.76 mmol, 1.0 equiv) in DMF (20.0 mL) was added DIPEA (1.23 g,9.5 mmol, 2 equiv) and HATU (2.17 g, 5.720 mmol, 1.20 equiv) at 0° C.After the reaction mixture was stirred at 0° C. for 20 min,(3R)-thiomorpholin-3-ylmethanol (0.70 g, 5.243 mmol, 1.1 equiv) wasadded in portions. The resulting solution was stirred for 2 h at 25° C.The reaction was then quenched by the addition of 50 mL of water. Theresulting solution was extracted with 3×80 mL of ethyl acetate, driedover anhydrous sodium sulfate, and concentrated under vacuum. Theresidue was purified by silica gel column chromatography using ethylacetate/petroleum ether (1:100 to 1:1) as eluent. This resulted in[(3R)-4-(2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol.LCMS (ES) [M+1]⁺ m/z: 535.2.

Step 2

Into a 250-mL 3-necked round-bottom flask purged and maintained with aninert atmosphere of argon, was placed[(3R)-4-(2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methanol(1.5 g, 2.8 mmol, 1.0 equiv), 2,6-dihydroxybenzaldehyde (0.43 g, 3.1mmol, 1.1 equiv), DCM (150.00 mL) and PPh3 (1.1 g, 4.2 mmol, 1.5 equiv).After the reaction was cooled to 0° C., a solution of DBAD (0.78 g, 3.36mmol, 1.2 equiv) in DCM (10 mL) was added dropwise. The resultingsolution was stirred for 16 h at 0 to 25° C. The resulting mixture wasconcentrated under vacuum. The residue was purified by silica gel columnchromatography with ethyl acetate/petroleum ether (1:100 to 1:5) aseluent. This resulted in1-[[(3R)-4-(2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde.LCMS (ES) [M+1] m/z: 655.2; ¹H-NMR: (300 MHz, DMSO-d6, ppm): δ 11.76(br, 1H), 10.39 (br, 1H), 8.54-8.48 (m, 1H), 7.86-7.27(m, 13H),6.78-6.55 (m, 2H), 5.41 (br, 1H), 4.83-4.44 (m, 3H), 3.39-3.14 (m, 4H),3.10-2.70 (m, 3H), 2.41-2.11 (m, 1H), 1.02-0.81 (m, 12H).

Step 3

Into a 100-mL 3-necked round-bottom flask, was placed2-[[(3R)-4-(2-[2-[(tert-butyldiphenylsilyl)oxy]propyl]pyridine-3-carbonyl)thiomorpholin-3-yl]methoxy]-6-hydroxybenzaldehyde(1.0 g, 1.52 mmol, 1.0 eq.) and THF (10 mL). After the reaction wascooled to 0° C., a solution of TEA3HF (1.0 g, 80.9 mmol, 3.0 equiv) wasadded dropwise. The resulting solution was stirred for 5 h at 45° C. ThepH value of the solution was adjusted to 8 with NaHCO₃ (2 mol/L). Thereaction was extracted with ethyl acetate (50 mL×3), and the organiclayers combined and concentrated. The crude product was purified bysilica gel column chromatography eluted with PE/EA=100:1 to 1:1 to givethe racemate product.

The racemate product was purified by Chiral-HPLC (Conditions: Column:LuxAmylose-1, 50*250 mm, 10 um; Mobile phase: A:n-Hexane B:Ethanol; Flowrate: 90 mL/min; Gradient:50% B in 36min; 220 nm) and was analyzed byanalytical HPLC (Conditions: Instrument: SHIMADZU LC-20AT; Mobile PhaseA: n-Hexane; Mobile Phase B: Ethanol; Conc. of Phase B: 50.0%; FlowRate: 1.000 mL/min; Column Lux Amylose-1, 4.6*100 mm, 3 μm; Column ID:H18-344853). This resulted in Compound 44, Diastereomer 1 and Compound44, Diastereomer 2.

Data for Compound 44, Diastereomer 1: Chiral HPLC retention time=4.85min; LCMS (ES, m/z): [M+H]⁺: 417.2; ¹H-NMR: (300 MHz, DMSO-d6, ppm): δ11.77 (br, 1H), 10.33 (s, 1H), 8.56 (dd, J=1.8, 4.8 Hz, 1H), 7.76-7.29(m, 3H), 6.75-6.55 (m, 2H), 5.43-5.41 (m, 1H), 4.81-4.13 (m, 4H),3.49-3.41 (m, 2H), 3.11-2.41(m, 6H) , 1.08-0.92 (m, 3H).

Data for Compound 44, Diastereomer 2: Chiral HPLC retention time 6.94min; LCMS (ES, m/z): [M+H]⁺: 417.2; ¹H-NMR: (300 MHz, DMSO-d6, ppm): δ10.33 (s, 1H), 8.57-8.48 (m, 1H), 7.80-7.27 (m, 3H), 6.75-6.54 (m, 2H),5.53-41 (m, 1H), 4.56-4.06 (m, 4H), 3.58-3.40 (m, 2H), 3.15-2.67(m, 5H),2.43-2.38 (m, 1H), 1.14-0.89 (m, 3H).

Compounds 6-9, and 18 in Table 3 were synthesized according to themethods described herein and appropriate modifications thereof.

TABLE 3 Mass Compound Spectrometry Number Structure Data 6

384.1 (MH+) 7

386.2 (MH+) 8

387.1 (MH+) 9

371.1 (MH+) 18

LCMS (ES) [M + 1]⁺ m/z 399.2

Biological Assays

Whole blood assay: Oxygen equilibrium curves (OECs) were collected usinga TCS Hemox Analyzer (TCS Scientific Company, New Hope, Pa., USA) tomeasure changes in the binding affinity of O₂ to Hb. Whole blood wasincubated for 1 h at 37° C. with the indicated compounds in an equimolarratio of hemoglobin to compound and diluted into TES(2-[[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]amino]ethanesulfonicacid)/saline buffer prior to measurements. For example, for whole bloodat 20% hematocrit [Hct], which corresponds to 1 mM Hb, a compoundconcentration of 1 mM was used (for example, for compounds 1-5), and theincubated sample diluted 50- to 100-fold. The concentration forcompounds 6-44 (Diastereomers 1 and 2) varied but remained in equimolarratio to hemoglobin. The diluted samples were then oxygenated withcompressed air within the Hemox Analyzer and the OECs were collectedduring deoxygenation as previously described (Guarnone et al.,Haematologica, 1995, 80, 426-430). p50 (partial pressure of O₂ at whichHb is 50% saturated with 02) values were obtained using a non-linearregression analysis. Percentage change in p50 [Δ50 (%)] was calculatedas follows: Δp50 (%)=[(p50 of control)−p50 with compound)/p50control]×100. Resulting data is shown in Table 4. Enantiomer 1 andEnantiomer 2 of Compound 13 also exhibit a 450 of about 61.0% to about80.6%.

TABLE 4 Compound Delta-p50 Number (%)  1 77.3   2 84.4   3 85.8   475.5   5 81.0   6 74.5   7 62.7   8 79.8   9 62.2  10 (Enantiomer 1)65.6  10 (Enantiomer 2) 87.3  11 79.3  12 76.7  13 (Enantiomer 1) 80.6 13 (Enantiomer 2) 61.0  14 74.56 15 80.5  16 49.55 17 27.09 18 79.67 1954.67 20 78.32 21 60.21 22 70.32 23 70.92 24 65.51 25 53.36 26 51.72 2766.58 28 83.35 29 78.79 30 74.19 31 74.03 32 60.55 33 49.03 34 79.46 34(Diastereomer 1) 80.43 34 (Diastereomer 2) 81.59 35 (Diastereomer 1)81.35 35 (Diastereomer 2) 83.1  36 77.04 37 60.58 38 60.85 39 77.98 4072.82 40 (Enantiomer 1) 64.31 40 (Enantiomer 2) 83.36 41(Diastereomer 1) 66.71 41 (Diastereomer 2) 53.94 42 (Diastereomer 1)76.39 42 (Diastereomer 2) 75.05 43 (Diastereomer 1) 64.50 43(Diastereomer 2) 64.56 44 (Diastereomer 1) 66.57 44 (Diastereomer 2)54.34

CYP (PXR) Assay: PXR nuclear receptor activation utilizingstably-transfected human hepatoma cell lines (DPX2) were seeded in a96-well plate. Twenty-four hours after seeding, the cells were treatedwith selected concentrations of compounds in duplicate wells, and cellsthen returned to the incubator for an additional 24 h. At the end ofthis incubation period, the number of viable cells/well were determinedusing Promega's Cell Titer Fluor cytotoxicity assay. Subsequently,Promega's ONE-Glo were added to the same wells and reporter geneactivity were assessed. The average luminescent units for each compounddose of two replicates were divided by the average for the DMSO solventcontrol to determine the fold-induction. In accordance with industrystandard, a threshold of >2.5-fold was used to flag compounds that havein vivo CYP induction risk.

Structures of reference compounds (Compound A, Compound B, and CompoundC) are shown below in Table 5.

TABLE 5 Reference Compound A Reference Compound B Reference Compound CStructure

Results for various compounds disclosed herein and select referencecompounds are summarized in Table 6.

TABLE 6 CYP (PXR) Compound Flag Reference Compound A Y ReferenceCompound B Y Reference Compound C Y¹  1 N¹  8 N 12 N Compound 13(Enantiomer 1) N CYP (PXR) Flag based on fold PXR activation (human, at30 μM): Y, PXR activation ≥ 2.5-fold; N, PXR activation < 2.5-fold. ¹at25 μM.

Rat PK: A group of fasted male Sprague-Dawley rats were dosed via oralgavage at 10 mg/kg with test articles formulated in 0.5% methylcellulosesuspension. Blood samples were collected through jugular vein atpre-selected time points. Blood samples were prepared by proteinprecipitation with ACN, vortexed and then centrifuged beforesupernatants were transferred for bioanalysis. Test articleconcentrations were measured by HPLC-MS-MS. Pharmacokinetic parameterswere calculated using non-compartment analysis. The blood/plasma ratiowas calculated by dividing the AUC_(last) (i.e., the area under thecurve calculated from t=0 to the last detectable time-point) in blood bythe AUC_(last) in plasma. The T_(1/2) was calculated via a linearregression of the terminal phase of the blood-time concentrationprofile.

Results for various compounds disclosed herein and select referencecompounds (Compound A and Compound B) are summarized in Table 7.

TABLE 7 T_(1/2) Blood/Plasma Compound (h) ratio Reference 29    75Compound A Reference 29.8   98 Compound B  1 58   162  8 69   105 10112    212 (Enantiomer 2) 11 55   126 12 58   131 20 65    45 23 62   59 36 56   115 39 52    52 40 117    424 (Enantiomer 2) 13 88   230(Enantiomer 1) 35 102    493 (Diastereomer 1) 35 89   636 (Diastereomer2)

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs.

The inventions illustratively described herein may suitably be practicedin the absence of any element or elements, limitation or limitations,not specifically disclosed herein. Thus, for example, the terms“comprising”, “including,” “containing”, etc. shall be read expansivelyand without limitation. Additionally, the terms and expressions employedherein have been used as terms of description and not of limitation, andthere is no intention in the use of such terms and expressions ofexcluding any equivalents of the features shown and described orportions thereof, but it is recognized that various modifications arepossible within the scope of the invention claimed.

All publications, patent applications, patents, and other referencesmentioned herein are expressly incorporated by reference in theirentirety, to the same extent as if each were incorporated by referenceindividually. In case of conflict, the present specification, includingdefinitions, will control.

1.-20. (canceled)
 21. A method for increasing oxygen affinity ofhemoglobin S in a subject in need thereof, comprising administering tothe subject a therapeutically effective amount of a compound of formula:

or a pharmaceutically acceptable salt thereof.
 22. The method of claim21, comprising administering to the subject a therapeutically effectiveamount of a compound of formula:


23. A method for treating a disorder mediated by hemoglobin in a subjectin need thereof, comprising administering to the subject atherapeutically effective amount of a compound of formula:

or a pharmaceutically acceptable salt thereof.
 24. The method of claim23, comprising administering to the subject a therapeutically effectiveamount of a compound of formula:


25. The method of claim 23, wherein the hemoglobin is sickle hemoglobin.26. A method for treating sickle cell disease in a subject in needthereof, comprising administering to the subject a therapeuticallyeffective amount of a compound of formula:

or a pharmaceutically acceptable salt thereof.
 27. The method of claim26, comprising administering to the subject a therapeutically effectiveamount of a compound of formula: